How to add elements to php array

In PHP, an array is a very important data type that can hold a set of related values, and each value can be accessed through a unique key. In actual development, it is often necessary to add elements to an array. This article will introduce how to add elements to a PHP array.

1. Use the array_push() function to add elements to the end of the array

array_push() function can add one or more values ​​to the end of the array. The syntax of this function is as follows:

array_push($array, $value1, $value2, ...);

Among them, $array represents the array to which elements are to be added, and $value1, $value2, ... represent the elements to be added. Sample code:

// 定义一个空数组
$arr = array();

// 使用 array_push() 函数向数组中添加元素
array_push($arr, 'apple', 'banana', 'orange');

// 输出数组的所有元素
print_r($arr);

After executing the above code, the output result is:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

2. Use the [] or array[] operator to add elements to the end of the array

In PHP version 5.4 and above, you can use the [] or array[] operator to add elements to the end of the array, for example:

// 定义一个空数组
$arr = array();

// 使用 [] 或 array[] 运算符向数组中添加元素
$arr[] = 'apple';
$arr[] = 'banana';
$arr[] = 'orange';

// 输出数组的所有元素
print_r($arr);

After executing the above code, the output result is the same as the above sample code.

3. Add elements to the array using associative arrays

Associative arrays can use strings as key names to access the values ​​in the array through the key names. The method of adding elements to an associative array is similar to that of a normal array. For example:

// 定义一个空的关联数组
$arr = array();

// 使用下标添加元素
$arr['name'] = '张三';
$arr['age'] = 20;

// 输出数组的所有元素
print_r($arr);

After executing the above code, the output result is:

Array
(
    [name] => 张三
    [age] => 20
)

4. Use the array_unshift() function to add to the beginning of the array Element

array_unshift() function is used to add one or more elements to the beginning of an array. The syntax of this function is as follows:

array_unshift($array, $value1, $value2, ...);

where $array represents the array to which elements are to be added, $value1, $value2, ... represents the elements to be added. Sample code:

// 定义一个数组
$arr = array('banana', 'orange');

// 使用 array_unshift() 函数向数组开头添加元素
array_unshift($arr, 'apple');

// 输出数组的所有元素
print_r($arr);

After executing the above code, the output result is:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

5. Summary

This article introduces how to add elements to a PHP array, including using array_push( ) function, the [] or array[] operator to add elements to the end of an array, associative arrays to add elements to an array, and the array_unshift() function to add elements to the beginning of an array. In actual development, developers can choose a suitable method to add elements according to specific needs.

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