How to use json object array in php

JSON is a common data format that represents data in an easy-to-understand way and facilitates data transmission and parsing. In PHP, using JSON object arrays is very convenient, allowing us to quickly parse and process JSON format data. This article will introduce in detail how PHP uses JSON object arrays.

1. How PHP generates a JSON object array

You can use the json_encode function in PHP to convert a PHP array into a JSON object. For example, the following is a PHP array definition:

$data = array(
    "name" => "Tom",
    "age" => 20,
    "gender" => "male"
);

It can be converted into a JSON object in the following way:

$json = json_encode($data);

In the above code, the json_encode function accepts a PHP array as a parameter and generates A JSON object.

2. How PHP parses JSON object array

PHP provides a very simple method to parse JSON object array. You can use the json_decode function to convert a JSON object into a PHP array. For example, we have the following JSON string:

$json = '{"name":"Tom","age":20,"gender":"male"}';

It can be parsed into a PHP array using the following method:

$data = json_decode($json, true);

In the above code, the json_decode function accepts a JSON string as parameter and Returns a PHP array. If the second parameter is set to true, an associative array is returned, otherwise an object is returned.

3. How PHP operates on JSON object array

Before operating on JSON object array, it needs to be parsed into a PHP array first. In PHP arrays, array elements can be accessed through key names and key values. For example, if we have the following array of JSON objects:

$json = '[{"name":"Tom","age":20,"gender":"male"},{"name":"Amy","age":18,"gender":"female"}]';

First we need to parse it into a PHP array:

$data = json_decode($json, true);

The elements in the PHP array can be accessed via:

echo $data[0]["name"]; //输出 "Tom"

For an array containing multiple JSON objects, you can use a loop to traverse the elements. For example, you can use the foreach statement to iterate through each element in the array:

foreach ($data as $item) {
    echo $item["name"].", ".$item["age"]." years old, ".$item["gender"]."<br>";
}

In the above code, the $item variable represents an element in the array, and an associative array is used to access the key value.

4. How to save an array of JSON objects to a file in PHP

In PHP, you can use the file_put_contents function to save an array of JSON objects to a file. For example, if we have the following array of JSON objects:

$json = '[{"name":"Tom","age":20,"gender":"male"},{"name":"Amy","age":18,"gender":"female"}]';

It can be saved to a file using the following method:

file_put_contents("data.json", $json);

In the above code, the file_put_contents function accepts two parameters, the first The parameter indicates the file path to save to, and the second parameter indicates the JSON string to be saved.

5. How PHP reads an array of JSON objects from a file

In PHP, you can use the file_get_contents function to read an array of JSON objects from a file. For example, if we save the previously saved array of JSON objects to the "data.json" file, we can read it using the following code:

$json = file_get_contents("data.json");

In the above code, the file_get_contents function accepts a parameter indicating that we want to read The file path to take. After the read is successful, you can use the method introduced before to parse it into a PHP array and perform operations.

6. Summary

This article introduces how PHP uses JSON object arrays, including generating JSON object arrays, parsing JSON object arrays, operating JSON object arrays, and saving JSON object arrays to files. Zhonghe reads an array of JSON objects from a file. By studying this article, I believe that readers have mastered the basic skills of using JSON object arrays in PHP, and can use them flexibly in actual development.

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