How to determine if a file exists in jquery

The jquery method to determine whether a file exists: first encapsulate a fileExists method and receive url parameters; then use the [$.ajax()] method to send a request, set a synchronous request; and finally return the request result.

The operating environment of this tutorial: Windows 7 system, jquery version 3.2.1. This method is suitable for all brands of computers.

Related recommendations: "jQuery Video Tutorial"

Jquery method to determine whether a file exists:

js or jquery judgment Whether the file exists, you need to use ajax

Steps:

1. Encapsulate a fileExists method and receive url parameters;

2. Use $.ajax() Method to send a request and set the synchronous mode request;

3. Return the request result.

function fileExists(url) {
     var isExists;
     $.ajax({
         url: url,
         async: false,
         type: 'HEAD',
         error: function () {
             isExists = 0;
         },
         success: function () {
             isExists = 1;
         }
     });
     if (isExists == 1) {
         return true;
     } else {
         return false;
     }
}

Usage

var Exists=Exists('/cache/view_num/' + uid + '.txt');
if(Exists){
    alert('存在')
}

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