How to output the value of js array in php

PHP is a widely used server-side scripting language that can be used to generate dynamic web pages and web applications. When developing web applications, you often need to pass data from PHP to JavaScript for processing and rendering, which includes outputting the values ​​of a JavaScript array.

This article will introduce how to use PHP to output the value of a JavaScript array.

1. Directly output JavaScript array

In PHP, if you need to output a simple JavaScript array, you can use the following code to operate:

<?php $array = array("apple", "orange", "banana");

echo "<script>var jsArray = ".json_encode($array).";";

?>

In the above code, we first define a PHP array $array, which contains three string elements. Then, use the json_encode() function to convert this array into a JSON-formatted string and assign it to the JavaScript variable jsArray.

Finally, use PHP’s echo statement to output the generated JavaScript code to the web page. This allows you to pass data from PHP to JavaScript.

2. Output JavaScript Array via AJAX

If you need to dynamically load a JavaScript array obtained from PHP, you can use AJAX to do it.

In PHP, you need to write a script that handles AJAX requests and returns a JSON object containing a JavaScript array.

<?php // 处理 AJAX 请求
if (isset($_POST[&#39;action&#39;]) && $_POST[&#39;action&#39;] == &#39;getArray&#39;) {
    $array = array("apple", "orange", "banana");
    echo json_encode($array);
}

?>

In the above code, we define an AJAX request named getArray, and specify the request processing script as ajax.php in the request.

In AJAX, you need to use the XMLHttpRequest object to send the request and get the JavaScript array from the response after the request is completed.

var xhr = new XMLHttpRequest();

xhr.onreadystatechange = function() {
    if (xhr.readyState == 4 && xhr.status == 200) {
        var jsArray = JSON.parse(xhr.responseText);
        console.log(jsArray);
    }
};

xhr.open('POST', 'ajax.php', true);
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
xhr.send('action=getArray');

In the above code, we first create an XMLHttpRequest object named xhr and define its onreadystatechange event. In the event response function, if the request status is 4 (indicating that the request has been completed) and the status code is 200 (indicating that the request is successful), the response text is parsed into a JavaScript object and output into the console.

Then call the xhr.open() method to open a POST request, and specify the PHP script for AJAX request processing as ajax.php. Send the request in the send() method, specifying the request parameters as 'action=getArray'.

In summary, through the above two methods, data in PHP can be passed to JavaScript arrays for processing and rendering.

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