继续收藏一些PHP常用函数_php技巧
方便以后制作php程序，直接拿来就可以用了，其实一些好的函数都在一些较成熟的cms系统中都有，例如dedecms，帝国cms,phpcms等，不论是gb2312的还是utf8格式的都有。
<?
function GetIP() { //获取IP
if ($_SERVER["HTTP_X_FORWARDED_FOR"])
$ip = $_SERVER["HTTP_X_FORWARDED_FOR"];
else if ($_SERVER["HTTP_CLIENT_IP"])
$ip = $_SERVER["HTTP_CLIENT_IP"];
else if ($_SERVER["REMOTE_ADDR"])
$ip = $_SERVER["REMOTE_ADDR"];
else if (getenv("HTTP_X_FORWARDED_FOR"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else if (getenv("HTTP_CLIENT_IP"))
$ip = getenv("HTTP_CLIENT_IP");
else if (getenv("REMOTE_ADDR"))
$ip = getenv("REMOTE_ADDR");
else
$ip = "Unknown";
return $ip;
}
?><?php
function DateAdd($date, $int, $unit = "d") { //时间的增加（还可以改进成时分秒都可以增加，有时间再补上）
$dateArr = explode("-", $date);
$value[$unit] = $int;
return date("Y-m-d", mktime(0,0,0, $dateArr[1] + $value['m'], $dateArr[2] + $value['d'], $dateArr[0] + $value['y']));
}
function GetWeekDay($date) { //计算出给出的日期是星期几
$dateArr = explode("-", $date);
return date("w", mktime(0,0,0,$dateArr[1],$dateArr[2],$dateArr[0]));
}
?><?
function check_date($date) { //检查日期是否合法日期
$dateArr = explode("-", $date);
if (is_numeric($dateArr[0]) && is_numeric($dateArr[1]) && is_numeric($dateArr[2])) {
return checkdate($dateArr[1],$dateArr[2],$dateArr[0]);
}
return false;
}
function check_time($time) { //检查时间是否合法时间
$timeArr = explode(":", $time);
if (is_numeric($timeArr[0]) && is_numeric($timeArr[1]) && is_numeric($timeArr[2])) {
if (($timeArr[0] >= 0 && $timeArr[0] <= 23) && ($timeArr[1] >= 0 && $timeArr[1] <= 59) && ($timeArr[2] >= 0 && $timeArr[2] <= 59))
return true;
else
return false;
}
return false;
}
function DateDiff($date1, $date2, $unit = "") { //时间比较函数，返回两个日期相差几秒、几分钟、几小时或几天
switch ($unit) {
case 's':
$pidend = 1;
break;
case 'i':
$pidend = 60;
break;
case 'h':
$pidend = 3600;
break;
case 'd':
$pidend = 86400;
break;
default:
$pidend = 86400;
}
$time1 = strtotime($date1);
$time2 = strtotime($date2);
if ($time1 && $time2)
return (float)($time1 - $time2) / $pidend;
return false;
}
?>
PHP重定向
方法一：header("Location: index.php");
方法二：echo "<scrīpt>window.location ="$PHP_SELF";</scrīpt>";
方法三：echo "<META HTTP-EQUIV="Refresh" CONTENT="0; URL=index.php">";
?>获取访问者浏览器
<?
function browse_infor()
{
$browser="";$browserver="";
$Browsers =array("Lynx","MOSAIC","AOL","Opera","JAVA","MacWeb","WebExplorer","OmniWeb");
$Agent = $GLOBALS["HTTP_USER_AGENT"];
for ($i=0; $i<=7; $i++)
{
if (strpos($Agent,$Browsers[$i]))
{
$browser = $Browsers[$i];
$browserver ="";
}
}
if (ereg("Mozilla",$Agent) && !ereg("MSIE",$Agent))
{
$temp =explode("(", $Agent); $Part=$temp[0];
$temp =explode("/", $Part); $browserver=$temp[1];
$temp =explode(" ",$browserver); $browserver=$temp[0];
$browserver =preg_replace("/([d.]+)/","1",$browserver);
$browserver = " $browserver";
$browser = "Netscape Navigator";
}
if (ereg("Mozilla",$Agent) && ereg("Opera",$Agent))
{
$temp =explode("(", $Agent); $Part=$temp[1];
$temp =explode(")", $Part); $browserver=$temp[1];
$temp =explode(" ",$browserver);$browserver=$temp[2];
$browserver =preg_replace("/([d.]+)/","1",$browserver);
$browserver = " $browserver";
$browser = "Opera";
}
if (ereg("Mozilla",$Agent) && ereg("MSIE",$Agent))
{
$temp = explode("(", $Agent); $Part=$temp[1];
$temp = explode(";",$Part); $Part=$temp[1];
$temp = explode(" ",$Part);$browserver=$temp[2];
$browserver =preg_replace("/([d.]+)/","1",$browserver);
$browserver = " $browserver";
$browser = "Internet Explorer";
}
if ($browser!="")
{
$browseinfo = "$browser$browserver";
}
else
{
$browseinfo = "Unknown";
}
return $browseinfo;
}
//调用方法$browser=browseinfo() ;直接返回结果
?>获取访问者操作系统
<?
function osinfo() {
$os="";
$Agent = $GLOBALS["HTTP_USER_AGENT"];
if (eregi('win',$Agent) && strpos($Agent, '95')) {
$os="Windows 95";
}
elseif (eregi('win 9x',$Agent) && strpos($Agent, '4.90')) {
$os="Windows ME";
}
elseif (eregi('win',$Agent) && ereg('98',$Agent)) {
$os="Windows 98";
}
elseif (eregi('win',$Agent) && eregi('nt 5.0',$Agent)) {
$os="Windows 2000";
}
elseif (eregi('win',$Agent) && eregi('nt',$Agent)) {
$os="Windows NT";
}
elseif (eregi('win',$Agent) && eregi('nt 5.1',$Agent)) {
$os="Windows XP";
}
elseif (eregi('win',$Agent) && ereg('32',$Agent)) {
$os="Windows 32";
}
elseif (eregi('linux',$Agent)) {
$os="Linux";
}
elseif (eregi('unix',$Agent)) {
$os="Unix";
}
elseif (eregi('sun',$Agent) && eregi('os',$Agent)) {
$os="SunOS";
}
elseif (eregi('ibm',$Agent) && eregi('os',$Agent)) {
$os="IBM OS/2";
}
elseif (eregi('Mac',$Agent) && eregi('PC',$Agent)) {
$os="Macintosh";
}
elseif (eregi('PowerPC',$Agent)) {
$os="PowerPC";
}
elseif (eregi('AIX',$Agent)) {
$os="AIX";
}
elseif (eregi('HPUX',$Agent)) {
$os="HPUX";
}
elseif (eregi('NetBSD',$Agent)) {
$os="NetBSD";
}
elseif (eregi('BSD',$Agent)) {
$os="BSD";
}
elseif (ereg('OSF1',$Agent)) {
$os="OSF1";
}
elseif (ereg('IRIX',$Agent)) {
$os="IRIX";
}
elseif (eregi('FreeBSD',$Agent)) {
$os="FreeBSD";
}
if ($os=='') $os = "Unknown";
return $os;
}
//调用方法$os=os_infor() ;
?>文件格式类
<? $mime_types = array( 'gif' => 'image/gif', 'jpg' => 'image/jpeg', 'jpeg' => 'image/jpeg', 'jpe' => 'image/jpeg', 'bmp' => 'image/bmp', 'png' => 'image/png', 'tif' => 'image/tiff', 'tiff' => 'image/tiff', 'pict' => 'image/x-pict', 'pic' => 'image/x-pict', 'pct' => 'image/x-pict', 'tif' => 'image/tiff', 'tiff' => 'image/tiff', 'psd' => 'image/x-photoshop', 'swf' => 'application/x-shockwave-flash', 'js' => 'application/x-javascrīpt', 'pdf' => 'application/pdf', 'ps' => 'application/postscrīpt', 'eps' => 'application/postscrīpt', 'ai' => 'application/postscrīpt', 'wmf' => 'application/x-msmetafile', 'css' => 'text/css', 'htm' => 'text/html', 'html' => 'text/html', 'txt' => 'text/plain', 'xml' => 'text/xml', 'wml' => 'text/wml', 'wbmp' => 'image/vnd.wap.wbmp', 'mid' => 'audio/midi', 'wav' => 'audio/wav', 'mp3' => 'audio/mpeg', 'mp2' => 'audio/mpeg', 'avi' => 'video/x-msvideo', 'mpeg' => 'video/mpeg', 'mpg' => 'video/mpeg', 'qt' => 'video/quicktime', 'mov' => 'video/quicktime', 'lha' => 'application/x-lha', 'lzh' => 'application/x-lha', 'z' => 'application/x-compress', 'gtar' => 'application/x-gtar', 'gz' => 'application/x-gzip', 'gzip' => 'application/x-gzip', 'tgz' => 'application/x-gzip', 'tar' => 'application/x-tar', 'bz2' => 'application/bzip2', 'zip' => 'application/zip', 'arj' => 'application/x-arj', 'rar' => 'application/x-rar-compressed', 'hqx' => 'application/mac-binhex40', 'sit' => 'application/x-stuffit', 'bin' => 'application/x-macbinary', 'uu' => 'text/x-uuencode', 'uue' => 'text/x-uuencode', 'latex'=> 'application/x-latex', 'ltx' => 'application/x-latex', 'tcl' => 'application/x-tcl', 'pgp' => 'application/pgp', 'asc' => 'application/pgp', 'exe' => 'application/x-msdownload', 'doc' => 'application/msword', 'rtf' => 'application/rtf', 'xls' => 'application/vnd.ms-excel', 'ppt' => 'application/vnd.ms-powerpoint', 'mdb' => 'application/x-msaccess', 'wri' => 'application/x-mswrite', ); ?>
php生成excel文档
<?
header("Content-type:application/vnd.ms-excel");
header("Content-Disposition:filename=test.xls");
echo "test1t";
echo "test2tn";
echo "test1t";
echo "test2tn";
echo "test1t";
echo "test2tn";
echo "test1t";
echo "test2tn";
echo "test1t";
echo "test2tn";
echo "test1t";
echo "test2tn";
//改动相应文件头就可以输出.doc .xls等文件格式了
?>
时间比较问题
举一个简单例子说明:比如一个论坛对当天发表的贴子用new图片标记一下。
方法一：
<?
//$db->rows[$i][date]中为数据库中datetime字段值.
$today=time();
$theDay=date("Y-m-d H:i:s",$today-24*3600);
$newTag=$db->rows[$i][date]>=$theDay?"<img src='../image/newinfor.gif'>":"";
//方法二：
$newTag=$db->rows[$i][date]>=date("Y-m-d 00:00:00")?"<img src='../image/newinfor.gif'>":"";
?>//提取页面和浏览器提交的变量，作用相当于使PHP.INI开了全局变量
<? @extract($_SERVER, EXTR_SKIP); @extract($_SESSION, EXTR_SKIP); @extract($_POST, EXTR_SKIP); @extract($_FILES, EXTR_SKIP); @extract($_GET, EXTR_SKIP); @extract($_ENV, EXTR_SKIP); ?>
//读取文件函数
<?
function readfromfile($file_name) {
if (file_exists($file_name)) {
$filenum=fopen($file_name,"r");
flock($filenum,LOCK_EX);
$file_data=fread($filenum, filesize($file_name));
rewind($filenum);
fclose($filenum);
return $file_data;
}
}
?>//写入文件函数
<?
function writetofile($file_name,$data,$method="w") {
$filenum=fopen($file_name,$method);
flock($filenum,LOCK_EX);
$file_data=fwrite($filenum,$data);
fclose($filenum);
return $file_data;
}
?>//页面快速转向
<?
function turntopage($url="index.php",$info = "页面转向中...",$second=2){
print "<html>n<head>n<title>页面转向中....</title>n";
print "<meta http-equiv="refresh" content="$second;url=$url">n";
print "<style type="text/css">n<!--n";
print "td { font-family: "Verdana", "Arial";font-size: 12px}n";
print "A {COLOR: #000000; TEXT-DECORATION: none}n";
print "-->n</style>n";
print "</head>n<body>n";
print "<table width="100%" border="0" align="center">n";
print " <tr>n";
print " <td height="200"> </td>n";
print " </tr>n";
print " <tr>n";
print " <td align="center">n";
print " <table width="60%" border="0" cellpadding="8" bgcolor="#AA9FFF">n";
print " <tr>n";
print " <td height="30" align="center">页面转向提示信息</td>n";
print " </tr>n";
print " <tr>n";
print " <td align="center">$info</td>n";
print " </tr>n";
print " <tr>n";
print " <td align="center">n";
print " <a href="$url">如果你的浏览器不支持自动跳转,请按这里</a></td>n";
print " </tr>n";
print " </tr>n";
print " </table></td>n";
print " </tr>n";
print " <tr>n";
print " <td height="200"> </td>n";
print " </tr>n";
print "</table>n";
print "</body>n</html>";
exit;
?>产生随机字符串函数
<?
function random($length) {
$hash = @#@#;
$chars = @#ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz@#;
$max = strlen($chars) - 1;
mt_srand((double)microtime() * 1000000);
for($i = 0; $i < $length; $i++) {
$hash .= $chars[mt_rand(0, $max)];
}
return $hash;
}
?>截取一定长度的字符串（该函数对GB2312使用有效）
<? function Wordscut($string, $length ,$sss=0) { if(strlen($string) > $length) { if($sss){ $length=$length - 3; $addstr=@# ...@#; } for($i = 0; $i < $length; $i++) { if(ord($string[$i]) > 127) { $wordscut .= $string[$i].$string[$i + 1]; $i++; } else { $wordscut .= $string[$i]; } } return $wordscut.$addstr; } return $string; } ?>取得客户端IP地址
<?
function GetIP(){
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
$ip = getenv("HTTP_CLIENT_IP");
else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
$ip = getenv("REMOTE_ADDR");
else if (isset($_SERVER[@#REMOTE_ADDR@#]) && $_SERVER[@#REMOTE_ADDR@#] && strcasecmp($_SERVER[@#REMOTE_ADDR@#], "unknown"))
$ip = $_SERVER[@#REMOTE_ADDR@#];
else
$ip = "unknown";
return($ip);
}
?>
判断邮箱地址
<?
function checkEmail($inAddress)
{
return (ereg("^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+",$inAddress));
}
?>分页（两个函数配合使用）
<?
function getpage($sql,$page_size=20)
{
global $page,$totalpage,$sums; //out param
$page = $_GET["page"];
//$eachpage = $page_size;
$pagesql = strstr($sql," from ");
$pagesql = "select count(*) as ids ".$pagesql;
$result = mysql_query($pagesql);
if($rs = mysql_fetch_array($result)) $sums = $rs[0];
$totalpage = ceil($sums/$page_size);
if((!$page)($page<1)) $page=1;
$startpos = ($page-1)*$page_size;
$sql .=" limit $startpos,$page_size ";
return $sql;
}
function showbar($string="")
{
global $page,$totalpage;
$out="共<font ".$totalpage."color=@#red@#><b>".$totalpage."</b></font>页 ";
$linkNum =4;
$start = ($page-round($linkNum/2))>0 ? ($page-round($linkNum/2)) : "1";
$end = ($page+round($linkNum/2))<$totalpage ? ($page+round($linkNum/2)) : $totalpage;
$prestart=$start-1;
$nextend=$end+1;
if($page<>1)
$out .= "<a href=@#?page=1&&".$string."@#title=第一页>第一页</a> ";
if($start>1)
$out.="<a href=@#?page=".$prestart."@# title=上一页>..<<</a> ";
for($t=$start;$t<=$end;$t++)
{
$out .= ($page==$t) ? "<font [".$t."]color=@#red@#><b>[".$t."]</b></font> " : "<a $thref=@#?page=$t&&".$string."@#>$t</a> ";
}
if($end<$totalpage)
$out.="<a href=@#?page=".$nextend."&&".$string."@# title=下一页>>>..</a>";
if($page<>$totalpage)
$out .= " <a href=@#?page=".$totalpage."&&".$string."@# title=最后页>最后页</a>";
return $out;
}
?>
获取新插入数据的ID
<? mysql_insert_id(); ?>
//获得当前的脚本网址
<?
function get_php_url(){
if(!empty($_server["REQUEST_URI"])){
$scriptName = $_SERVER["REQUEST_URI"];
$nowurl = $scriptName;
}else{
$scriptName = $_SERVER["PHP_SELF"];
if(empty($_SERVER["QUERY_STRING"])) $nowurl = $scriptName;
else $nowurl = $scriptName."?".$_SERVER["QUERY_STRING"];
}
return $nowurl;
}
?>
//把全角数字转为半角数字
<?
function GetAlabNum($fnum){
$nums = array("０","１","２","３","４","５","６","７","８","９");
$fnums = "0123456789";
for($i=0;$i<=9;$i++) $fnum = str_replace($nums[$i],$fnums[$i],$fnum);
$fnum = ereg_replace("[^0-9.]|^0{1,}","",$fnum);
if($fnum=="") $fnum=0;
return $fnum;
}
?>
//去除HTML标记
<?
function Text2Html($txt){
$txt = str_replace(" "," ",$txt);
$txt = str_replace("<","<",$txt);
$txt = str_replace(">",">",$txt);
$txt = preg_replace("/[rn]{1,}/isU","
rn",$txt);
return $txt;
}
?>
//相对路径转化成绝对路径
<?
function relative_to_absolute($content, $feed_url) {
preg_match('/(http|https|ftp):///', $feed_url, $protocol);
$server_url = preg_replace("/(http|https|ftp|news):///", "", $feed_url);
$server_url = preg_replace("//.*/", "", $server_url);
if ($server_url == '') {
return $content;
}
if (isset($protocol[0])) {
$new_content = preg_replace('/href="//', 'href="'.$protocol[0].$server_url.'/', $content);
$new_content = preg_replace('/src="//', 'src="'.$protocol[0].$server_url.'/', $new_content);
} else {
$new_content = $content;
}
return $new_content;
}
?>//取得所有链接
<?
function get_all_url($code){
preg_match_all('/<as+href=["|']?([^>"' ]+)["|']?s*[^>]*>([^>]+)</a>/i',$code,$arr);
return array('name'=>$arr[2],'url'=>$arr[1]);
}
?>//HTML表格的每行转为CSV格式数组
<?
function get_tr_array($table) {
$table = preg_replace("'<td[^>]*?>'si",'"',$table);
$table = str_replace("</td>",'",',$table);
$table = str_replace("</tr>","{tr}",$table);
//去掉 HTML 标记
$table = preg_replace("'<[/!]*?[^<>]*?>'si","",$table);
//去掉空白字符
$table = preg_replace("'([rn])[s]+'","",$table);
$table = str_replace(" ","",$table);
$table = str_replace(" ","",$table);
$table = explode(",{tr}",$table);
array_pop($table);
return $table;
}
?>//将HTML表格的每行每列转为数组，采集表格数据
<? function get_td_array($table) { $table = preg_replace("'<table[^>]*?>'si","",$table); $table = preg_replace("'<tr[^>]*?>'si","",$table); $table = preg_replace("'<td[^>]*?>'si","",$table); $table = str_replace("</tr>","{tr}",$table); $table = str_replace("</td>","{td}",$table); //去掉 HTML 标记 $table = preg_replace("'<[/!]*?[^<>]*?>'si","",$table); //去掉空白字符 $table = preg_replace("'([rn])[s]+'","",$table); $table = str_replace(" ","",$table); $table = str_replace(" ","",$table); $table = explode('{tr}', $table); array_pop($table); foreach ($table as $key=>$tr) { $td = explode('{td}', $tr); array_pop($td); $td_array[] = $td; } return $td_array; } ?>//返回字符串中的所有单词 $distinct=true 去除重复
<?
function split_en_str($str,$distinct=true) {
preg_match_all('/([a-zA-Z]+)/',$str,$match);
if ($distinct == true) {
$match[1] = array_unique($match[1]);
}
sort($match[1]);
return $match[1];
}
?>
//打印出为本PHP项目做出贡献的人员的清单
<? string phpcredits(void) ?>
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1359
52
Quick start guide to commonly used functions in the pandas library
Jan 24, 2024 am 08:05 AM
The pandas library is a commonly used data processing and analysis tool in Python. It provides a wealth of functions and methods that can easily complete data import, cleaning, processing, analysis and visualization. This article will introduce a quick start guide to commonly used functions in the pandas library, with specific code examples. The data import pandas library can easily import data files in various formats through functions such as read_csv and read_excel. Here is a sample code: importpandas
An in-depth analysis of the Go language standard library: revealing the secrets of commonly used functions and data structures
Jan 30, 2024 am 09:46 AM
Explore the Go language standard library: Detailed explanation of common functions and data structures Introduction: Since its birth, the Go language has attracted the attention of many developers with its simplicity, efficiency, and concurrency. As a modern programming language, the Go language provides a wealth of functions and data structures in its standard library to help developers quickly build high-performance, reliable applications. This article will explore in detail some commonly used functions and data structures in the Go language standard library, and deepen understanding through specific code examples. 1. strings package: string processing function G
Common functions for PHP file operations
Jun 16, 2023 pm 01:15 PM
PHP is a widely used open source programming language that is widely used in the field of web development. In web development, file operation is an essential part, so it is very important to be proficient in PHP's file operation functions. In this article, we will introduce some functions commonly used in PHP file operations. fopen() The fopen() function is used to open a file or URL and returns the file pointer. It has two parameters: file name and opening method. The opening mode can be "r" (read-only mode), "w" (write mode), "a"
Comprehensive list of commonly used functions in the Numpy library: quick start and practice guide
Jan 19, 2024 am 08:57 AM
The Numpy library is one of the most commonly used data processing libraries in Python. It is widely loved by data analysts for its efficient and convenient operation methods. In the Numpy library, there are many commonly used functions that can help us complete data processing tasks quickly and efficiently. This article will introduce some commonly used Numpy functions, and provide code examples and practical application scenarios so that readers can get started with the Numpy library faster. 1. Create an array numpy.array function prototype: numpy.array(obj
What are the commonly used functions in the pandas library?
Nov 22, 2023 pm 01:36 PM
Commonly used functions in the pandas library include: 1. read_csv() and read_excel() functions; 2. head() and tail() functions; 3. info() function; 4. describe() function, etc. Detailed introduction: 1. read_csv() and read_excel() functions. These two functions are used to read data from CSV and Excel files. They can read the data into data frame objects to facilitate further data analysis; 2. head () and tail() functions, etc.
Proficient in C language functions: Comprehensive analysis of the usage and principles of commonly used functions
Feb 20, 2024 am 09:28 AM
Proficient in C language functions: Comprehensive analysis of the usage and principles of commonly used functions Abstract: Functions in C language are important tools for code reuse and modularization, and are also an indispensable part of programming. This article will comprehensively analyze the usage and principles of commonly used functions, including function definitions, calls and return values, as well as usage examples of common functions, to help readers better understand and master the use of C language functions. 1. Function definition and call 1.1 Function definition In C language, the function definition consists of return type, function name, parameter list and function body.
What are the most commonly used functions in PHP?
Apr 18, 2024 pm 02:24 PM
The most commonly used functions in PHP include: data operations: var_dump(), print_r(), array() string operations: strlen(), strtoupper(), substr() file processing: fopen(), fwrite(), fread( )Error handling: error_reporting(), trigger_error(), set_error_handler()
Application skills of PHP common function libraries
Jun 16, 2023 am 09:49 AM
PHP is a powerful programming language that is often used for web application development. In PHP, there are many commonly used function libraries that can help developers easily complete various operations. This article will introduce several commonly used function libraries and their application techniques. 1. String function library The string function library is generally used for string operations, including string length, string concatenation, string interception, etc. The following are several commonly used string functions: strlen() function is used to obtain the length of a string, for example: $str=&q
