Discuss how PHP converts json into an array (three methods)

PHP is a commonly used programming language that can convert JSON into an array, making data processing and management simpler and more efficient. Here are some methods and techniques to help developers quickly implement this operation.

1. Use the json_decode() function

In PHP, the json_decode() function can easily convert JSON format data into a PHP array. The specific syntax is as follows:

mixed json_decode ( string $json [, bool $assoc = false [, int $depth = 512 [, int $options = 0 ]]] )

Parameter description:

• $json: Pass in a JSON string;
• $assoc: (can Optional) The default is false, which means a stdClass object is returned; if set to true, an array is returned;
• $depth: (optional) indicates the maximum depth of recursion, which defaults to 512 Layer;
• $options: (optional) Set options when decoding, common ones are JSON_BIGINT_AS_STRING (convert large numbers into string type), JSON_OBJECT_AS_ARRAY (convert stdClass object into array) etc.

For example:

$json_str = '{"name":"Jack","age":30,"city":"Beijing"}';
$arr = json_decode($json_str, true);
print_r($arr);

The output result is:

Array (
    [name] => Jack
    [age] => 30
    [city] => Beijing
)

2. Use json_decode() function file_get_contents() function

Not only can you convert a JSON string to an array, you can also read JSON data from a file and convert it to an array. At this time, you can use the file_get_contents() function to read the contents of the JSON file, and then use the above-mentioned json_decode() function to achieve conversion.

For example:

$json_file = 'data.json';
$json_str = file_get_contents($json_file);
$arr = json_decode($json_str, true);
print_r($arr);

3. Use the json_decode() function curl library

If the JSON data is not in the local file, but is transmitted over the network, At this time, you can use the curl library to obtain JSON data, and then use the json_decode() function to implement conversion.

For example:

$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'https://api.example.com/data.json');
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($curl);
curl_close($curl);

$arr = json_decode($result, true);
print_r($arr);

The above code uses the curl library to request the https://api.example.com/data.json interface and convert the returned JSON data as an array and output the result.

Summary

This article introduces three methods of converting JSON data into PHP arrays, each with its own advantages and disadvantages. Developers can choose the appropriate method according to the actual situation. When using the json_decode() function, you also need to pay attention to decoding options, recursion depth, returned data type and other issues to avoid errors. I believe that by mastering these skills, the work efficiency of PHP developers will be significantly improved.

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