Home > Web Front-end > JS Tutorial > The authoritative guide to javascript study notes null and undefined_jquery

The authoritative guide to javascript study notes null and undefined_jquery

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB
Release: 2016-05-16 18:01:54
Original
1088 people have browsed it
Copy code The code is as follows:





javascript null and undefined</title> ; <BR></head> <br><body> <br><script type="text/javascript"> <br>/**<br>******************null keyword************************ <br>JavaScript The keyword null is a special value that means "no value". Null is often regarded as a special value of the object type, that is, a value that represents "no object". <br>null is a unique value that is different from all other values. If the value of a variable is null, it means that its value is not a valid object, array, number, string <br> and Boolean value. <br>When null is used in a boolean environment, it is automatically converted to false. When it is used in a numeric environment, it is automatically converted to the number 0. When it is used in a string environment, it is <br> Automatically converted to "null". <br>*/ <br>var $null = null ; <br>//For Boolean environment <br>if($null){ <br>document.write("When null is used in Boolean environment, no conversion is performed"); <br>}else{ <br>document .write("When null is used in a Boolean environment, it is automatically converted to false");//This sentence will be output<br>} <br>//Used in a numeric environment<br>if(0 $null = = 0){ <br>document.write("<br/>When null is used in a numeric environment, it is automatically converted to 0");//This sentence will be output<br>}else{ <br>Document.write("<br/>When null is used in a numeric environment, no conversion is performed"); <br>} <br>//Used in a string environment<br>document.write("<br />For string environment: "$null);//null <br>//typeof of null: object <br>document.write("<br/>The data type of $null is: " typeof $null);//object <br>/**<br>**********************undefined****************** <br>undefined is a special value, it Not a keyword in javascript. The following situations need to be noted: <br>1. When using a variable that has been declared but not yet assigned a value <br> 2. When using an object attribute that does not exist <br> In the above two cases, what is returned is This value is undefined. The undefined value is different from null. <br>When an undefined value is used in a Boolean environment, it is automatically converted to false; <br>When it is used in a numeric environment, it is automatically converted to NaN; (Interpretation of NaN :The NaN attribute is a special value that represents a non-numeric value. This attribute is used to indicate that a value is not a number. <br>When it is used in a string context, it is automatically converted to "undefined"; <br>*/ <br>var $aaa;//Declared but not initialized. <br>var $bbb = "Test";//Declared and initialized. <br>var $obj = new Object(); <br>document.write("<br/>$aaa's type: " typeof $aaa ", $aaa's value: " $aaa);//undefined , undefined <br>document.write("<br/>Type of $bbb: " typeof $bbb ", Value of $bbb: " $bbb);//string, test <br>document.write(" <br/>The type of a non-existent property myProp of $obj: " typeof $obj.myProp ", the value of $obj.myProp: " $obj.myProp);//undefined, undefined <br>// document.write("<br/>Output the value of an undeclared variable: " $abc);//Run error<br>/**<br>The connection between undefined and null <br>Although undefined and null values ​​are different, the == operator treats them as equal. <br>var obj = new Objec(); <br>obj.prop == null //return true <br>If you want to strictly distinguish between undefiend and null, you need to use the ==== operator or typeof <br> var obj = new Objec(); <br>obj.prop === null //return false <br>typeof obj.prop //output undefined <br>typeof null //output object <br>*/ <br></script> <br></body> <br></html> <br> </div> </div> </div> <div style="display: flex;"> <div class="wzconBq" style="display: inline-flex;"> <span>Related labels:</span> <div class="wzcbqd"> <a onclick="hits_log(2,'www',this);" href-data="https://www.php.cn/search?word=null" target="_blank">null</a> <a onclick="hits_log(2,'www',this);" href-data="https://www.php.cn/search?word=undefined" target="_blank">undefined</a> </div> </div> <!-- <div style="display: inline-flex;float: right; color:#333333;">source:php.cn</div> --> </div> <div class="wzconOtherwz"> <a href="https://www.php.cn/faq/19670.html" title="jquery implements how to automatically fix navigation that exceeds the display range to the top of the screen_jquery"> <span>Previous article:jquery implements how to automatically fix navigation that exceeds the display range to the top of the screen_jquery</span> </a> <a href="https://www.php.cn/faq/19672.html" title="70 Beautiful and friendly navigation menu design recommended for foreign websites_javascript skills"> <span>Next article:70 Beautiful and friendly navigation menu design recommended for foreign websites_javascript skills</span> </a> </div> <div class="wzconShengming"> <div class="bzsmdiv">Statement of this Website</div> <div>The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn</div> </div> <ins class="adsbygoogle" style="display:block" data-ad-format="autorelaxed" data-ad-client="ca-pub-5902227090019525" data-ad-slot="2507867629"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> <div class="wzconZzwz"> <div class="wzconZzwztitle">Latest Articles by Author</div> <ul> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771332.html">How LLMs Work: Pre-Training to Post-Training, Neural Networks, Hallucinations, and Inference</a> </div> <div>2025-02-26 03:58:14</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771322.html">I Combined the Blockchain and AI to Generate Art. Here’s What Happened Next.</a> </div> <div>2025-02-26 03:38:10</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771315.html">Advanced Prompt Engineering: Chain of Thought (CoT)</a> </div> <div>2025-02-26 03:17:10</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771302.html">Retrieval Augmented Generation in SQLite</a> </div> <div>2025-02-26 02:49:09</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771274.html">How to Use an LLM-Powered Boilerplate for Building Your Own Node.js API</a> </div> <div>2025-02-26 01:08:13</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771258.html">LLMs for Coding in 2024: Price, Performance, and the Battle for the Best</a> </div> <div>2025-02-26 00:46:10</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771227.html">Prompting Vision Language Models</a> </div> <div>2025-02-25 23:42:08</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771219.html">How to Measure the Reliability of a Large Language Model's Response</a> </div> <div>2025-02-25 22:50:13</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771209.html">An Illusion of Life</a> </div> <div>2025-02-25 21:54:11</div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots"></span> <a target="_blank" href="https://www.php.cn/faq/1796771201.html">Scientists Go Serious About Large Language Models Mirroring Human Thinking</a> </div> <div>2025-02-25 20:45:11</div> </li> </ul> </div> <div class="wzconZzwz"> <div class="wzconZzwztitle">Latest Issues</div> <div class="wdsyContent"> <div class="wdsyConDiv flexRow wdsyConDiv1"> <div class="wdcdContent flexColumn"> <a href="https://www.php.cn/wenda/.html" target="_blank" title="How to get NULL from `SELECT IF(NULL, 2, 3)` MySQL method" class="wdcdcTitle">How to get NULL from `SELECT IF(NULL, 2, 3)` MySQL method</a> <a href="https://www.php.cn/wenda/.html" class="wdcdcCons"></a> <div class="wdcdcInfo flexRow"> <div class="wdcdcileft"> <span class="wdcdciSpan"> From 1970-01-01 08:00:00</span> </div> <div class="wdcdciright flexRow"> <div class="wdcdcirdz flexRow ira"> <b class="wdcdcirdzi"></b>0 </div> <div class="wdcdcirpl flexRow ira"><b class="wdcdcirpli"></b>0</div> <div class="wdcdcirwatch flexRow ira"><b class="wdcdcirwatchi"></b>0</div> </div> </div> </div> </div> <div class="wdsyConLine wdsyConLine2"></div> <div class="wdsyConDiv flexRow wdsyConDiv1"> <div class="wdcdContent flexColumn"> <a href="https://www.php.cn/wenda/.html" target="_blank" title="undefined and null" class="wdcdcTitle">undefined and null</a> <a href="https://www.php.cn/wenda/.html" class="wdcdcCons"></a> <div class="wdcdcInfo flexRow"> <div class="wdcdcileft"> <span class="wdcdciSpan"> From 1970-01-01 08:00:00</span> </div> <div class="wdcdciright flexRow"> <div class="wdcdcirdz flexRow ira"> <b class="wdcdcirdzi"></b>0 </div> <div class="wdcdcirpl flexRow ira"><b class="wdcdcirpli"></b>0</div> <div class="wdcdcirwatch flexRow ira"><b class="wdcdcirwatchi"></b>0</div> </div> </div> </div> </div> <div class="wdsyConLine wdsyConLine2"></div> <div class="wdsyConDiv flexRow wdsyConDiv1"> <div class="wdcdContent flexColumn"> <a href="https://www.php.cn/wenda/.html" target="_blank" title="es6 Null conduction operator - es6 Null conduction operator" class="wdcdcTitle">es6 Null conduction operator - es6 Null conduction operator</a> <a href="https://www.php.cn/wenda/.html" class="wdcdcCons"></a> <div class="wdcdcInfo flexRow"> <div class="wdcdcileft"> <span class="wdcdciSpan"> From 1970-01-01 08:00:00</span> </div> <div class="wdcdciright flexRow"> <div class="wdcdcirdz flexRow ira"> <b class="wdcdcirdzi"></b>0 </div> <div class="wdcdcirpl flexRow ira"><b class="wdcdcirpli"></b>0</div> <div class="wdcdcirwatch flexRow ira"><b class="wdcdcirwatchi"></b>0</div> </div> </div> </div> </div> <div class="wdsyConLine wdsyConLine2"></div> <div class="wdsyConDiv flexRow wdsyConDiv1"> <div class="wdcdContent flexColumn"> <a href="https://www.php.cn/wenda/.html" target="_blank" title="Adding here will add null values. How can we prevent the added data from being null?" class="wdcdcTitle">Adding here will add null values. How can we prevent the added data from being null?</a> <a href="https://www.php.cn/wenda/.html" class="wdcdcCons"></a> <div class="wdcdcInfo flexRow"> <div class="wdcdcileft"> <span class="wdcdciSpan"> From 1970-01-01 08:00:00</span> </div> <div class="wdcdciright flexRow"> <div class="wdcdcirdz flexRow ira"> <b class="wdcdcirdzi"></b>0 </div> <div class="wdcdcirpl flexRow ira"><b class="wdcdcirpli"></b>0</div> <div class="wdcdcirwatch flexRow ira"><b class="wdcdcirwatchi"></b>0</div> </div> </div> </div> </div> <div class="wdsyConLine wdsyConLine2"></div> <div class="wdsyConDiv flexRow wdsyConDiv1"> <div class="wdcdContent flexColumn"> <a href="https://www.php.cn/wenda/.html" target="_blank" title="null problem" class="wdcdcTitle">null problem</a> <a href="https://www.php.cn/wenda/.html" class="wdcdcCons"></a> <div class="wdcdcInfo flexRow"> <div class="wdcdcileft"> <span class="wdcdciSpan"> From 1970-01-01 08:00:00</span> </div> <div class="wdcdciright flexRow"> <div class="wdcdcirdz flexRow ira"> <b class="wdcdcirdzi"></b>0 </div> <div class="wdcdcirpl flexRow ira"><b class="wdcdcirpli"></b>0</div> <div class="wdcdcirwatch flexRow ira"><b class="wdcdcirwatchi"></b>0</div> </div> </div> </div> </div> <div class="wdsyConLine wdsyConLine2"></div> </div> </div> <div class="wzconZt" > <div class="wzczt-title"> <div>Related Topics</div> <a href="https://www.php.cn/faq/zt" target="_blank">More> </a> </div> <div class="wzcttlist"> <ul> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/undefined"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072214274871494.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="what is undefined" /> </a> <a target="_blank" href="https://www.php.cn/faq/undefined" class="title-a-spanl" title="what is undefined"><span>what is undefined</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/cnulldqb"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072214050783807.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="The difference between null and NULL in c language" /> </a> <a target="_blank" href="https://www.php.cn/faq/cnulldqb" class="title-a-spanl" title="The difference between null and NULL in c language"><span>The difference between null and NULL in c language</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/javaznulldyf"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072212315015040.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="Usage of null in java" /> </a> <a target="_blank" href="https://www.php.cn/faq/javaznulldyf" class="title-a-spanl" title="Usage of null in java"><span>Usage of null in java</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/win7bnxjwjjjj"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072212322474336.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="How to solve the problem of not being able to create a new folder in Win7" /> </a> <a target="_blank" href="https://www.php.cn/faq/win7bnxjwjjjj" class="title-a-spanl" title="How to solve the problem of not being able to create a new folder in Win7"><span>How to solve the problem of not being able to create a new folder in Win7</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/midhsdsyff"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072214222752700.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="How to use the mid function" /> </a> <a target="_blank" href="https://www.php.cn/faq/midhsdsyff" class="title-a-spanl" title="How to use the mid function"><span>How to use the mid function</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/fwqqqcsjjff"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072212104364129.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="Server request timeout solution" /> </a> <a target="_blank" href="https://www.php.cn/faq/fwqqqcsjjff" class="title-a-spanl" title="Server request timeout solution"><span>Server request timeout solution</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/undefined"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072214274871494.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="what is undefined" /> </a> <a target="_blank" href="https://www.php.cn/faq/undefined" class="title-a-spanl" title="what is undefined"><span>what is undefined</span> </a> </li> <li class="ul-li"> <a target="_blank" href="https://www.php.cn/faq/cpqlmlynx"><img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/subject/202407/22/2024072213595990142.jpg?x-oss-process=image/resize,m_fill,h_145,w_220" alt="What are the disk cleanup commands?" /> </a> <a target="_blank" href="https://www.php.cn/faq/cpqlmlynx" class="title-a-spanl" title="What are the disk cleanup commands?"><span>What are the disk cleanup commands?</span> </a> </li> </ul> </div> </div> </div> </div> <div class="phpwzright"> <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-5902227090019525" data-ad-slot="3653428331" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> <div class="wzrOne"> <div class="wzroTitle">Popular Recommendations</div> <div class="wzroList"> <ul> <li> <div class="wzczzwzli"> <span class="layui-badge-dots wzrolr"></span> <a style="height: auto;" title="what does js mean" href="https://www.php.cn/faq/482163.html">what does js mean</a> </div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots wzrolr"></span> <a style="height: auto;" title="How to convert string to array in js?" href="https://www.php.cn/faq/461802.html">How to convert string to array in js?</a> </div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots wzrolr"></span> <a style="height: auto;" title="How to refresh the page using javascript" href="https://www.php.cn/faq/473330.html">How to refresh the page using javascript</a> </div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots wzrolr"></span> <a style="height: auto;" title="How to delete an item in js array" href="https://www.php.cn/faq/475790.html">How to delete an item in js array</a> </div> </li> <li> <div class="wzczzwzli"> <span class="layui-badge-dots wzrolr"></span> <a style="height: auto;" title="How to use sqrt function" href="https://www.php.cn/faq/415276.html">How to use sqrt function</a> </div> </li> </ul> </div> </div> <script src="https://sw.php.cn/hezuo/cac1399ab368127f9b113b14eb3316d0.js" type="text/javascript"></script> <div class="wzrThree"> <div class="wzrthree-title"> <div>Popular Tutorials</div> <a target="_blank" href="https://www.php.cn/course.html">More> </a> </div> <div class="wzrthreelist swiper2"> <div class="wzrthreeTab swiper-wrapper"> <div class="check tabdiv swiper-slide" data-id="one">Related Tutorials <div></div></div> <div class="tabdiv swiper-slide" data-id="two">Popular Recommendations<div></div></div> <div class="tabdiv swiper-slide" data-id="three">Latest courses<div></div></div> </div> <ul class="one"> <li> <a target="_blank" href="https://www.php.cn/course/812.html" title="The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/041/620debc3eab3f377.jpg" alt="The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)"/> </a> <div class="wzrthree-right"> <a target="_blank" title="The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)" href="https://www.php.cn/course/812.html">The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)</a> <div class="wzrthreerb"> <div>1436854 <b class="kclbcollectb"></b></div> <div class="courseICollection" data-id="812"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/74.html" title="PHP introductory tutorial one: Learn PHP in one week" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/6253d1e28ef5c345.png" alt="PHP introductory tutorial one: Learn PHP in one week"/> </a> <div class="wzrthree-right"> <a target="_blank" title="PHP introductory tutorial one: Learn PHP in one week" href="https://www.php.cn/course/74.html">PHP introductory tutorial one: Learn PHP in one week</a> <div class="wzrthreerb"> <div>4296506 <b class="kclbcollectb"></b></div> <div class="courseICollection" data-id="74"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/286.html" title="JAVA Beginner's Video Tutorial" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/62590a2bacfd9379.png" alt="JAVA Beginner's Video Tutorial"/> </a> <div class="wzrthree-right"> <a target="_blank" title="JAVA Beginner's Video Tutorial" href="https://www.php.cn/course/286.html">JAVA Beginner's Video Tutorial</a> <div class="wzrthreerb"> <div>2662764 <b class="kclbcollectb"></b></div> <div class="courseICollection" data-id="286"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/504.html" title="Little Turtle's zero-based introduction to learning Python video tutorial" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/62590a67ce3a6655.png" alt="Little Turtle's zero-based introduction to learning Python video tutorial"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Little Turtle's zero-based introduction to learning Python video tutorial" href="https://www.php.cn/course/504.html">Little Turtle's zero-based introduction to learning Python video tutorial</a> <div class="wzrthreerb"> <div>516479 <b class="kclbcollectb"></b></div> <div class="courseICollection" data-id="504"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/2.html" title="PHP zero-based introductory tutorial" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/6253de27bc161468.png" alt="PHP zero-based introductory tutorial"/> </a> <div class="wzrthree-right"> <a target="_blank" title="PHP zero-based introductory tutorial" href="https://www.php.cn/course/2.html">PHP zero-based introductory tutorial</a> <div class="wzrthreerb"> <div>877116 <b class="kclbcollectb"></b></div> <div class="courseICollection" data-id="2"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> </ul> <ul class="two" style="display: none;"> <li> <a target="_blank" href="https://www.php.cn/course/812.html" title="The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/041/620debc3eab3f377.jpg" alt="The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)"/> </a> <div class="wzrthree-right"> <a target="_blank" title="The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)" href="https://www.php.cn/course/812.html">The latest ThinkPHP 5.1 world premiere video tutorial (60 days to become a PHP expert online training course)</a> <div class="wzrthreerb"> <div >1436854 times of learning</div> <div class="courseICollection" data-id="812"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/286.html" title="JAVA Beginner's Video Tutorial" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/62590a2bacfd9379.png" alt="JAVA Beginner's Video Tutorial"/> </a> <div class="wzrthree-right"> <a target="_blank" title="JAVA Beginner's Video Tutorial" href="https://www.php.cn/course/286.html">JAVA Beginner's Video Tutorial</a> <div class="wzrthreerb"> <div >2662764 times of learning</div> <div class="courseICollection" data-id="286"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/504.html" title="Little Turtle's zero-based introduction to learning Python video tutorial" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/62590a67ce3a6655.png" alt="Little Turtle's zero-based introduction to learning Python video tutorial"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Little Turtle's zero-based introduction to learning Python video tutorial" href="https://www.php.cn/course/504.html">Little Turtle's zero-based introduction to learning Python video tutorial</a> <div class="wzrthreerb"> <div >516479 times of learning</div> <div class="courseICollection" data-id="504"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/901.html" title="Quick introduction to web front-end development" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/067/64be28a53a4f6310.png" alt="Quick introduction to web front-end development"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Quick introduction to web front-end development" href="https://www.php.cn/course/901.html">Quick introduction to web front-end development</a> <div class="wzrthreerb"> <div >217099 times of learning</div> <div class="courseICollection" data-id="901"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/234.html" title="Master PS video tutorials from scratch" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/068/62611f57ed0d4840.jpg" alt="Master PS video tutorials from scratch"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Master PS video tutorials from scratch" href="https://www.php.cn/course/234.html">Master PS video tutorials from scratch</a> <div class="wzrthreerb"> <div >920977 times of learning</div> <div class="courseICollection" data-id="234"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> </ul> <ul class="three" style="display: none;"> <li> <a target="_blank" href="https://www.php.cn/course/1648.html" title="[Web front-end] Node.js quick start" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png" alt="[Web front-end] Node.js quick start"/> </a> <div class="wzrthree-right"> <a target="_blank" title="[Web front-end] Node.js quick start" href="https://www.php.cn/course/1648.html">[Web front-end] Node.js quick start</a> <div class="wzrthreerb"> <div >9637 times of learning</div> <div class="courseICollection" data-id="1648"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/1647.html" title="Complete collection of foreign web development full-stack courses" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/067/6628cc96e310c937.png" alt="Complete collection of foreign web development full-stack courses"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Complete collection of foreign web development full-stack courses" href="https://www.php.cn/course/1647.html">Complete collection of foreign web development full-stack courses</a> <div class="wzrthreerb"> <div >7754 times of learning</div> <div class="courseICollection" data-id="1647"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/1646.html" title="Go language practical GraphQL" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/067/662221173504a436.png" alt="Go language practical GraphQL"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Go language practical GraphQL" href="https://www.php.cn/course/1646.html">Go language practical GraphQL</a> <div class="wzrthreerb"> <div >6581 times of learning</div> <div class="courseICollection" data-id="1646"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/1645.html" title="550W fan master learns JavaScript from scratch step by step" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/067/662077e163124646.png" alt="550W fan master learns JavaScript from scratch step by step"/> </a> <div class="wzrthree-right"> <a target="_blank" title="550W fan master learns JavaScript from scratch step by step" href="https://www.php.cn/course/1645.html">550W fan master learns JavaScript from scratch step by step</a> <div class="wzrthreerb"> <div >831 times of learning</div> <div class="courseICollection" data-id="1645"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> <li> <a target="_blank" href="https://www.php.cn/course/1644.html" title="Python master Mosh, a beginner with zero basic knowledge can get started in 6 hours" class="wzrthreelaimg"> <img class="lazy" src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/course/000/000/067/6616418ca80b8916.png" alt="Python master Mosh, a beginner with zero basic knowledge can get started in 6 hours"/> </a> <div class="wzrthree-right"> <a target="_blank" title="Python master Mosh, a beginner with zero basic knowledge can get started in 6 hours" href="https://www.php.cn/course/1644.html">Python master Mosh, a beginner with zero basic knowledge can get started in 6 hours</a> <div class="wzrthreerb"> <div >32380 times of learning</div> <div class="courseICollection" data-id="1644"> <b class="nofollow small-nocollect"></b> </div> </div> </div> </li> </ul> </div> <script> var mySwiper = new Swiper('.swiper2', { autoplay: false,//可选选项,自动滑动 slidesPerView : 'auto', }) $('.wzrthreeTab>div').click(function(e){ $('.wzrthreeTab>div').removeClass('check') $(this).addClass('check') $('.wzrthreelist>ul').css('display','none') $('.'+e.currentTarget.dataset.id).show() }) </script> </div> <div class="wzrFour"> <div class="wzrfour-title"> <div>Latest Downloads</div> <a href="https://www.php.cn/xiazai">More> </a> </div> <script> $(document).ready(function(){ var sjyx_banSwiper = new Swiper(".sjyx_banSwiperwz",{ speed:1000, autoplay:{ delay:3500, disableOnInteraction: false, }, pagination:{ el:'.sjyx_banSwiperwz .swiper-pagination', clickable :false, }, loop:true }) }) </script> <div class="wzrfourList swiper3"> <div class="wzrfourlTab swiper-wrapper"> <div class="check swiper-slide" data-id="onef">Web Effects <div></div></div> <div class="swiper-slide" data-id="twof">Website Source Code<div></div></div> <div class="swiper-slide" data-id="threef">Website Materials<div></div></div> <div class="swiper-slide" data-id="fourf">Front End Template<div></div></div> </div> <ul class="onef"> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="jQuery enterprise message form contact code" href="https://www.php.cn/toolset/js-special-effects/8071">[form button] jQuery enterprise message form contact code</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="HTML5 MP3 music box playback effects" href="https://www.php.cn/toolset/js-special-effects/8070">[Player special effects] HTML5 MP3 music box playback effects</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="HTML5 cool particle animation navigation menu special effects" href="https://www.php.cn/toolset/js-special-effects/8069">[Menu navigation] HTML5 cool particle animation navigation menu special effects</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="jQuery visual form drag and drop editing code" href="https://www.php.cn/toolset/js-special-effects/8068">[form button] jQuery visual form drag and drop editing code</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="VUE.JS imitation Kugou music player code" href="https://www.php.cn/toolset/js-special-effects/8067">[Player special effects] VUE.JS imitation Kugou music player code</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="Classic html5 pushing box game" href="https://www.php.cn/toolset/js-special-effects/8066">[html5 special effects] Classic html5 pushing box game</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="jQuery scrolling to add or reduce image effects" href="https://www.php.cn/toolset/js-special-effects/8065">[Picture special effects] jQuery scrolling to add or reduce image effects</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a target="_blank" title="CSS3 personal album cover hover zoom effect" href="https://www.php.cn/toolset/js-special-effects/8064">[Photo album effects] CSS3 personal album cover hover zoom effect</a> </div> </li> </ul> <ul class="twof" style="display:none"> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8328" title="Home Decor Cleaning and Repair Service Company Website Template" target="_blank">[Front-end template] Home Decor Cleaning and Repair Service Company Website Template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8327" title="Fresh color personal resume guide page template" target="_blank">[Front-end template] Fresh color personal resume guide page template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8326" title="Designer Creative Job Resume Web Template" target="_blank">[Front-end template] Designer Creative Job Resume Web Template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8325" title="Modern engineering construction company website template" target="_blank">[Front-end template] Modern engineering construction company website template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8324" title="Responsive HTML5 template for educational service institutions" target="_blank">[Front-end template] Responsive HTML5 template for educational service institutions</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8323" title="Online e-book store mall website template" target="_blank">[Front-end template] Online e-book store mall website template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8322" title="IT technology solves Internet company website template" target="_blank">[Front-end template] IT technology solves Internet company website template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8321" title="Purple style foreign exchange trading service website template" target="_blank">[Front-end template] Purple style foreign exchange trading service website template</a> </div> </li> </ul> <ul class="threef" style="display:none"> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3078" target="_blank" title="Cute summer elements vector material (EPS PNG)">[PNG material] Cute summer elements vector material (EPS PNG)</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3077" target="_blank" title="Four red 2023 graduation badges vector material (AI EPS PNG)">[PNG material] Four red 2023 graduation badges vector material (AI EPS PNG)</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3076" target="_blank" title="Singing bird and cart filled with flowers design spring banner vector material (AI EPS)">[banner picture] Singing bird and cart filled with flowers design spring banner vector material (AI EPS)</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3075" target="_blank" title="Golden graduation cap vector material (EPS PNG)">[PNG material] Golden graduation cap vector material (EPS PNG)</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3074" target="_blank" title="Black and white style mountain icon vector material (EPS PNG)">[PNG material] Black and white style mountain icon vector material (EPS PNG)</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3073" target="_blank" title="Superhero silhouette vector material (EPS PNG) with different color cloaks and different poses">[PNG material] Superhero silhouette vector material (EPS PNG) with different color cloaks and different poses</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3072" target="_blank" title="Flat style Arbor Day banner vector material (AI+EPS)">[banner picture] Flat style Arbor Day banner vector material (AI+EPS)</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-materials/3071" target="_blank" title="Nine comic-style exploding chat bubbles vector material (EPS+PNG)">[PNG material] Nine comic-style exploding chat bubbles vector material (EPS+PNG)</a> </div> </li> </ul> <ul class="fourf" style="display:none"> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8328" target="_blank" title="Home Decor Cleaning and Repair Service Company Website Template">[Front-end template] Home Decor Cleaning and Repair Service Company Website Template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8327" target="_blank" title="Fresh color personal resume guide page template">[Front-end template] Fresh color personal resume guide page template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8326" target="_blank" title="Designer Creative Job Resume Web Template">[Front-end template] Designer Creative Job Resume Web Template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8325" target="_blank" title="Modern engineering construction company website template">[Front-end template] Modern engineering construction company website template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8324" target="_blank" title="Responsive HTML5 template for educational service institutions">[Front-end template] Responsive HTML5 template for educational service institutions</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8323" target="_blank" title="Online e-book store mall website template">[Front-end template] Online e-book store mall website template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8322" target="_blank" title="IT technology solves Internet company website template">[Front-end template] IT technology solves Internet company website template</a> </div> </li> <li> <div class="wzrfourli"> <span class="layui-badge-dots wzrflr"></span> <a href="https://www.php.cn/toolset/website-source-code/8321" target="_blank" title="Purple style foreign exchange trading service website template">[Front-end template] Purple style foreign exchange trading service website template</a> </div> </li> </ul> </div> <script> var mySwiper = new Swiper('.swiper3', { autoplay: false,//可选选项,自动滑动 slidesPerView : 'auto', }) $('.wzrfourlTab>div').click(function(e){ $('.wzrfourlTab>div').removeClass('check') $(this).addClass('check') $('.wzrfourList>ul').css('display','none') $('.'+e.currentTarget.dataset.id).show() }) </script> </div> </div> </div> <footer> <div class="footer"> <div class="footertop"> <img src="/static/imghw/logo.png" alt=""> <p>Public welfare online PHP training,Help PHP learners grow quickly!</p> </div> <div class="footermid"> <a href="https://www.php.cn/about/us.html">About us</a> <a href="https://www.php.cn/about/disclaimer.html">Disclaimer</a> <a href="https://www.php.cn/update/article_0_1.html">Sitemap</a> </div> <div class="footerbottom"> <p> © php.cn All rights reserved </p> </div> </div> </footer> <input type="hidden" id="verifycode" value="/captcha.html"> <script>layui.use(['element', 'carousel'], function () {var element = layui.element;$ = layui.jquery;var carousel = layui.carousel;carousel.render({elem: '#test1', width: '100%', height: '330px', arrow: 'always'});$.getScript('/static/js/jquery.lazyload.min.js', function () {$("img").lazyload({placeholder: "/static/images/load.jpg", effect: "fadeIn", threshold: 200, skip_invisible: false});});});</script> <script src="/static/js/common_new.js"></script> <script type="text/javascript" src="/static/js/jquery.cookie.js?1741683651"></script> <script src="https://vdse.bdstatic.com//search-video.v1.min.js"></script> <link rel='stylesheet' id='_main-css' href='/static/css/viewer.min.css?2' type='text/css' media='all'/> <script type='text/javascript' src='/static/js/viewer.min.js?1'></script> <script type='text/javascript' src='/static/js/jquery-viewer.min.js'></script> <script type="text/javascript" src="/static/js/global.min.js?5.5.53"></script> <!-- Matomo --> <script> var _paq = window._paq = window._paq || []; /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ _paq.push(['trackPageView']); _paq.push(['enableLinkTracking']); (function() { var u="https://tongji.php.cn/"; _paq.push(['setTrackerUrl', u+'matomo.php']); _paq.push(['setSiteId', '9']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); })(); </script> <!-- End Matomo Code --> </body> </html>