How to delete elements in an array in php

There are many ways to delete specified elements in an array in PHP. Here are a few common methods.

1. unset function
   The unset function can delete the specified element in the array or the entire array.

   $array = array(1, 2, 3, 4, 5);
   unset($array[2]); // 删除数组中下标为 2 的元素
   print_r($array); // 输出：Array ( [0] => 1 [1] => 2 [3] => 4 [4] => 5 )

2. array_splice function
   array_splice function can delete the elements in the specified interval in the array and return the deleted element array.

   $array = array(1, 2, 3, 4, 5);
   $removed = array_splice($array, 2, 1); // 从下标为 2 的元素开始删除 1 个元素
   print_r($array); // 输出：Array ( [0] => 1 [1] => 2 [2] => 4 [3] => 5 )
   print_r($removed); // 输出：Array ( [0] => 3 )

3. array_diff function
   array_diff function can return the difference set of two arrays, thereby achieving the effect of deleting the specified element.

   $array = array(1, 2, 3, 4, 5);
   $removed = array_diff($array, array(3)); // 删除值为 3 的元素
   print_r($removed); // 输出：Array ( [0] => 1 [1] => 2 [3] => 4 [4] => 5 )

4. array_filter function
   array_filter function can filter the elements in the array based on the return value of the callback function, thereby achieving the effect of deleting the specified element.

   // 根据键值来判断是否删除元素
   $array = array(1, 2, 3, 4, 5);
   $removed = array_filter($array, function($val) {
    return $val !== 3;
   });
   print_r($removed); // 输出：Array ( [0] => 1 [1] => 2 [3] => 4 [4] => 5 )
   
   // 根据键名来判断是否删除元素
   $array = array('a' => 1, 'b' => 2, 'c' => 3);
   $removed = array_filter($array, function($key) {
    return $key !== 'c';
   }, ARRAY_FILTER_USE_KEY);
   print_r($removed); // 输出：Array ( [a] => 1 [b] => 2 )

The above are several commonly used methods to delete array elements. You need to choose according to the actual situation when using them.

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