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How to assign php array to js

PHPz

Release： 2023-04-20 09:35:54

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php Arrays are a convenient way to store and manage data. One of the frequently used data types. In the process of web development, we often need to pass the value of the php array to JavaScript for use. In this article, we will introduce several ways to assign php arrays to JavaScript.

1. Use the json_encode() function

json_encode() function is a function that converts a PHP value into a JSON string. Because JavaScript supports JSON format, we can use json_encode() The function converts the php array into JSON string format so that JavaScript can read it. The following is a simple sample code:

$php_array = array("apple", "banana", "orange");//PHP数组
$json_array = json_encode($php_array);//将PHP数组转换成json格式的字符串

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Next, we output $json_array into JavaScript:

var js_array = <?php echo $json_array; ?>;//将php中的json格式字符串转换成JavaScript中的数组对象
alert(js_array[0]);//输出apple

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This method is very simple and easy to understand, and can easily pass the php array to in JavaScript. But be aware that if the php array contains Chinese or other special characters, encoding problems may occur.

2. Use string splicing method

Another common method is to create a JavaScript string in php, which contains an assignment operation to assign the value of the php array to the JavaScript array. This approach can sometimes be more flexible. The following is a sample code:

$php_array = array("apple", "banana", "orange");//PHP数组
$js_array = "[" . implode(",", $php_array) . "]";//将php数组拼接成JavaScript数组格式的字符串

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Next, we use the $js_array variable in JavaScript:

var js_array = <?php echo $js_array; ?>;//将拼接的JavaScript数组字符串变量直接输出
alert(js_array[0]);//输出apple

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This method is easier to understand. Convert the php array to String in JavaScript array format and then used directly.

3. Use Ajax to implement asynchronous requests

The last way is to use Ajax asynchronous requests. This method can get the value of a PHP array and assign it to a JavaScript variable without refreshing the page. The following is a sample code:

<?php
$php_array = array("apple", "banana", "orange");//PHP数组 

if(isset($_GET[&#39;action&#39;]) && $_GET[&#39;action&#39;] == &#39;get_array&#39;){
  echo json_encode($php_array);//将PHP数组转换成json格式的字符串，并输出
  exit;
}
?>

<html>
<head>
<script type="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript">
  $(document).ready(function(){
    $.getJSON("example.php?action=get_array", function(data){
      //使用jQuery的getJSON方法异步获取php中的json字符串
      var js_array = data;//将获取到的json字符串转换成JavaScript的数组对象
      alert(js_array[0]);
    });
  });
</script> 
</head>
<body>
  <h1>Hello, PHP 数组赋值给 JavaScript</h1>
</body>
</html>

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The above code assigns the PHP array to JavaScript in the Ajax success callback function. Get the backend json string through an asynchronous request and convert it into a JavaScript array object. This method can obtain the latest data without refreshing the page. However, it should be noted that this method requires the server to support Ajax, and compatibility issues may also occur in some lower version browsers.

Summary

This article introduces three methods of assigning php arrays to JavaScript. Each method has its advantages and disadvantages. We can choose the appropriate method according to the actual situation. Normally, we will use the json_encode() function or string concatenation. If we need to obtain the value of a PHP array in real time and update it continuously, then we can use the powerful library function Ajax.

No matter which method is used, we need to ensure that the PHP array being passed is complete and correct to avoid causing any errors during the transfer process. At the same time, you also need to pay attention to encoding issues to avoid conversion problems with Chinese or other special characters. I hope this article will be helpful to you in your learning or development process.

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