ajax发送POST两次，从PHP接收双重/重复结果

i found out my JS sends POST method twice to my PHP file, thats why i keep getting double/repetitive results from my PHP.

This JS event, upon .keyup() will execute an ajax.

    $(document).ready(function() {  
    var getUrl = $('#url');
    var youtube = regex here
    var web = regex here    

        getUrl.keyup(function() {

        if  (youtube.test(getUrl.val())) {
        var youtube_url = getUrl.val().match(youtube)[0];
        $.ajax ({
                type:"POST",
            url:"getyoutube.php",
            data: {youtube_url:youtube_url},
            success: function(html) { $('.echotest').append(html); }
        }); }

    else if (web.test(getUrl.val())) {
        var extracted_url = getUrl.val().match(web)[0];                 
                    $.post("curl_fetch.php?url="+ extracted_url, {
                }, function(response){
           $('#loader').html($(response).fadeIn('slow'));
           $('#cur_image').val(1);
        });} 
    }); 
}); 

the data will be received by getyoutube.php and should only print json result of a particular youtube video once.

 //some code ommitted
 $youtube ="https://gdata.youtube.com/feeds/api/videos/'.$matches[0].'?v=2&alt=jsonc";
 $curl = curl_init($youtube);
 curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
 $return = curl_exec($curl);
 curl_close($curl);
 $test = json_decode($return, true);
 print_r($test);

i cant seem to figure out why my AJAX post keeps sending POSTS method twice

Couple of things to try:

1) Make sure you bind and unbind your key up event

2) Use a global variable to make sure only one ajax request gets sent at once

i.e.:

var ajaxrequest = false; //GLOBAL

function getyoutubedata(){

  if(ajaxrequest != false){
     return;  
  }

  ajaxrequest = $.ajax ({
        type:"POST",
        url:"./includes/getyoutube.php",
        data: {youtube_url:youtube_url},
        success: function(html) { $('.echotest').append(html); ajaxrequest = false; }
  });

}

Btw thing to note the youtube api supports jsonp callbacks so you might want to consider doing this through that

3) Try to check if the content of the input field has changed even before calling the above function

You should show us the code with the .keyup() event, probably that's the place of an error. The event handler could execute a wrapper function for the ajax, instead of the ajax directly. For example, if you the keyup event is triggered, try to check if the input content has changed. If so, run ajax, if not - do nothing.

coverted this

 $.ajax ({
       type:"POST",
       url:"getyoutube.php",
       data: {youtube_url:youtube_url},
       success: function(html) { $('.echotest').append(html); }
        }); }   

to this.

$.post("./includes/getyoutube.php?url="+ youtube_url, {
    }, function(response){
    $('.echotest').append(response);
    });

POST method is now being executed once. although i cant really explain technically why it worked.