How to convert php to json array

PHP is a server-side scripting language that is very popular in web development and is mainly used for dynamic website development. JSON (JavaScript Object Notation) is a lightweight data exchange format that has become one of the most commonly used data formats in modern web applications due to its ease of reading and writing. In web development, we usually need to convert data in PHP scripts into JSON format and then pass it to the client or use JavaScript for processing.

PHP provides some built-in functions to convert PHP arrays or objects into JSON format. In this article, we'll cover how to convert a PHP array to a JSON array, as well as some common problems and solutions.

Convert PHP array to JSON array

PHP provides a built-in function json_encode(), which can convert PHP array to JSON format. If you want to convert a PHP array to JSON format, you only need to pass the array as a parameter to this function, for example:

<?php $arr = array(&#39;name&#39;=>'Tom', 'age'=>25);
echo json_encode($arr);
?>

The above example code will output the following data in JSON format:

{"name":"Tom","age":25}

Problems encountered and solutions

Problem 1: Chinese garbled characters

In some cases, Chinese garbled characters may appear in the JSON format we obtain after conversion. This is because the json_encode() function uses the ASCII character set by default and does not support the Unicode character set, and Chinese is a character in the Unicode character set, so garbled characters will appear.

To solve this problem, you can use the second parameter of the json_encode() function to specify the character set, for example, set it to UTF-8:

<?php $arr = array(&#39;name&#39;=>'Tom', 'age'=>25);
echo json_encode($arr, JSON_UNESCAPED_UNICODE);
?>

where The JSON_UNESCAPED_UNICODE constant represents unescaped Unicode characters and is output as is, thereby solving the problem of Chinese garbled characters.

Problem 2: Some special characters cannot be output normally

Some special characters, such as slashes, backslashes, single quotes, double quotes, etc., may not be output normally after conversion, resulting in JSON There is a format error. This problem can be solved by using PHP's escape character function, for example:

<?php $arr = array(&#39;name&#39;=>'Tom', 'age'=>25, 'desc'=>"I'm a \"good\" boy.");
echo json_encode($arr);
?>

In the above example, we used the escape character \ to escape the double quotes in the string , thereby solving the problem of output errors.

Question 3: There are data types that JSON cannot recognize in the array

Some PHP arrays contain data types that JSON cannot recognize, such as resource type (Resource), object type (Object), empty Type (NULL), etc. These data types are automatically converted to null when converted to JSON format. If you don't want this to happen, you can process these data types before conversion, for example:

<?php $arr = array(&#39;name&#39;=>'Tom', 'age'=>25, 'is_login'=>true, 'last_login'=>null, 'desc'=>'demo text', 'resource'=>fopen('file.txt', 'r'));
$arr = handleArr($arr);
echo json_encode($arr);

function handleArr($arr) {
    foreach($arr as $key=>$val) {
        if(is_resource($val)) {
            unset($arr[$key]);
        } elseif(is_object($val)) {
            $arr[$key] = handleArr((array)$val);
        } elseif(is_null($val)) {
            $arr[$key] = '';
        }
    }
    return $arr;
}
?>

In the above example, we used a custom function handleArr() to process the array special data type to avoid conversion to null.

Summary

With PHP’s built-in json_encode() function, we can easily convert PHP arrays into JSON format arrays. If you encounter problems such as Chinese garbled characters, special characters that cannot be output, and unrecognized data types, you can solve these problems by setting the second parameter and using escape characters, custom processing functions, etc. In actual development, we need to pay more attention to handling these issues to ensure that the converted JSON array can be correctly passed to the client or JavaScript for processing.

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