How to delete the key value of an array in php

In PHP, we need to operate arrays from time to time. Sometimes we need to delete one or some key values ​​in the array. In this case, we need to use PHP's built-in function unset(). The unset() function can delete one or more array elements. If there are multiple elements, the key names (indexes) need to be separated by commas.

The following is an example code for using the unset() function to delete an array key value:

// 定义一个数组
$array = array(
   'name' => '张三',
   'age' => 18,
   'sex' => '男',
);

// 删除一个键值
unset($array['age']);

// 删除多个键值
unset($array['name'], $array['sex']);

// 输出结果
var_dump($array);

Output result:

array(0) {
}

We can see from the above code that using unset The () function is very simple to delete an array key value. You only need to pass in the key name (index) of the element to be deleted.

It is worth noting that when we use the unset() function to delete an array element, if the element is the last element in the array, the unset() function will not change the array size, and the maximum size of the array will not be changed. The key name is still the key name of the deleted element. If we need to reset the array index, we need to use the array_values() function to rearrange the key names of the array.

The following is a sample code that uses the array_values() function to reset the array index:

// 重置数组索引
$new_array = array_values($array);

// 输出结果
var_dump($new_array);

Output result:

array(0) {
}

After using the array_values() function, we can see the array There are no elements left in .

The final reminder is that when using the unset() function to delete array elements, we need to pay attention to the array index, especially for associative arrays, to avoid deleting elements that we do not want to delete.

In summary, using the unset() function to delete array key values ​​is very simple, but you need to pay attention to the details. In daily PHP development, when encountering similar array operation requirements, we can choose the appropriate PHP built-in function to handle it according to the specific needs. This not only increases program readability, but also improves development efficiency.

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