javascript中的计数数组 [英] Count array in javascript

问题描述

大家好，我想问一下您如何计算数组的大小?我有一个数组，该数组从我的php文件传递的json_encode值中获取其值...这是我的php返回json数据的格式

Hi guys i would like to ask how do you count the size of an array? i have an array that gets its value from the json_encode value passed by my php file... here is the format of my php return json data

<?php
$idArr= array();
while($row= mysql_fetch_array($outputArrayResult)){			
  $idArr["" . $row[''id'']] = false;
}
			

echo json_encode(array("total_pages" => $num_pages,"ids" => $idArr));
?>

它以这种格式返回

which returns in this format

/* firebug output */

{
"total_pages":12,
"ids":{"1":false,"2":false,"3":false,"4":false,"5":false,"6":false,"7":false,"8":false,"9":false,"10":false,"11":false,"12":false}
}

现在在我的JavaScript中，我处理使用此代码返回的ajax数据

now in my javascript i handle the ajax data returned using this code

/* ajax request success handler */
success: function(data){	
  var obj = jQuery.parseJSON(data);
  var ids= obj.ids;
  alert("this is " + ids.length + " -- " + ids["2"]);
}

如您所见，我使用jQuery.parseJSON(data)检索数据并将其传递给我的变量ID.现在，当我尝试提醒该值时，它将为我提供此输出

as you can see im retrieving the data using jQuery.parseJSON(data) and pass it to my variable ids. now when i try to alert the value it gives me this output

/* alert message */
this is undefined -- false

因此，这意味着它成功检索了ids ["2"]的值，但是我无法获取要正确输出的数组的长度...您如何做到这一点?

so it means it successfully retrieved the value of ids["2"] but i cant get the length of the array to output properly... how do you do this?

推荐答案

idArr = array(); while(

idArr= array(); while(

row = mysql_fetch_array(

row= mysql_fetch_array(

outputArrayResult)){

outputArrayResult)){

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