The placement position of scrip in html-HTML Tutorial-php.cn

I used to think that script can be placed anywhere in HTML. I corrected my misconception when I made a request today - the position of script cannot be placed casually.

First of all, I want to implement a select tag with two options: yes and no. However, during initialization, the select tag is required to select a null value by default, so I added a method to let it change the null value when clicking. Delete:

<!DOCTYPE html>  

    <html>  

    <head>  

    <script src="jquery/jquery-1.11.1.min.js"></script>  

    </head>  

    <script>  

    $(&#39;#checkcash&#39;).click(function () {   

            if ($(&#39;#checkcash&#39;).val() == &#39;0&#39;) {   

                $("#checkcash option[value=&#39;0&#39;]").remove();   

            }   

        });   

        $("#alert").click(function(){   

        alert("1123");   

        })   

    </script>  

    <body>  

     是否已提现 <select id="checkcash"   style="width: 181px">  

                                <option selected="selected" value="0"></option>  

                                <option value="1">是</option>  

                                <option value="2">否</option>  

                                </select>  

                                    

                                <input type=&#39;button&#39; id=&#39;alert&#39; value="anwo">  

    </body>  

      

      

    </html>

Copy after login

But this does not achieve the desired effect. At first I thought it was a jquery syntax error and I kept checking and correcting it online, but it didn’t work. , and then suddenly I thought about whether I should put the script at the back. I tried it, and it turned out to be ok. Then I suddenly realized that it was not like this.

Later I checked the reason because the html file is executed in a top-down manner, but the order of the imported css and javascript is different. When the css is introduced and loaded, the program is still executed downwards, and When the