How to remove elements from an array in php?

php method to remove elements from an array: 1. Use the unset function to delete an element and keep the original index unchanged; 2. Use the [array_splice] function to delete an element without keeping the index; 3. Use the [array_diff] function to delete multiple elements by value, keeping the index.

php method to remove elements from an array:

1. Delete an element and keep it original The index remains unchanged

Use the unset function, the example is as follows:

<?php
  $array = array(0 => "a", 1 => "b", 2 => "c");
  unset($array[1]);
        //↑ 你想删除的key
?>

Output:

Array (
    [0] => a
    [2] => c
)

Using unset does not change the original value of the array There is an index. If you plan to rearrange the index (let the index start from 0 and be continuous), you can use the array_values function:

$array = array_values($array);
/*
输出
array(2) 
{ [0]=> string(1) "a" [1]=> 
string(1) "c"}
*/

2. Delete an element without keeping the index

Use the array_splice function, the example is as follows:

<?php
  $array = array(0 => "a", 1 => "b", 2 => "c");
  array_splice($array, 1, 1);
            //↑ 你想删除的元素的Offset
?>

Output:

Array (
    [0] => a
    [1] => c
)

3. Delete multiple elements by value, keeping the index

Use the array_diff function, the example is as follows:

<?php
  $array = array(0 => "a", 1 => "b", 2 => "c");
  $array = array_diff($array, ["a", "c"]);
               //└────────┘→ 你想删除的数组元素值values
?>

Output:

Array (
    [1] => b
)

Similar to unset, array_diff will also be maintained index.

4. Delete multiple elements by key and keep the index

Use the array_diff_key function, the example is as follows:

<?php
 
  $array = array(0 => "a", 1 => "b", 2 => "c");
  $array = array_diff_key($array, [0 => "xy", "2" => "xy"]);
                  //↑      ↑ 你想删除的数组键keys
?>

Output:

Array (
    [1] => b
)

Similar to unset, array_diff_key will also maintain the index.

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