Pass PHP var to JQUERY

问题

I am trying to pass a PHP variable to JQUERY. I tried the following script but the var 'id' is not been passed to upload_avatar.php. Guess i am making some mistake. Can anyone help me.

$(document).ready(function (e) {
    $("#uploadForm").on('submit',(function(e) {
        e.preventDefault();
        var id = '<?php echo $id; ?>';
        $.ajax({
            url: "upload_avatar.php",
            type: "POST",
            data:  new FormData(this)
            contentType: false,
            cache: false,
            processData:false,
            success: function(data)
            {
            $("#targetLayer").html(data);
            },
            error: function() 
            {
            }           
       });
    }));
});

回答1:

Append your id in formData as below

$(document).ready(function (e) {
    $("#uploadForm").on('submit',(function(e) {
        e.preventDefault();
        var id = '<?php echo $id; ?>';
        var frmData = new FormData(this);
        frmData.append('id', id);
        $.ajax({
            url: "upload_avatar.php",
            type: "POST",
            data:  frmData ,
            contentType: false,
            cache: false,
            processData:false,
            success: function(data)
            {
            $("#targetLayer").html(data);
            },
            error: function() 
            {
            }           
       });
    }));
});

回答2:

change your code to:

$(document).ready(function (e) {
$("#uploadForm").on('submit',(function(e) {
    e.preventDefault();
    var id = '<?php echo $id; ?>';
      var myFormData = new FormData();
       myFormData.append('id', id);
    $.ajax({

        url: "upload_avatar.php",
        contentType: false,
        cache: false,
        processData:false,
        data: myFormData,
        dataType: "json",

        success: function(data)
        {
        $("#targetLayer").html(data);
        },
        error: function() 
        {
        }           
   });
}));

});

来源：https://stackoverflow.com/questions/58269241/pass-php-var-to-jquery