What are the functions to delete array elements in php?

The functions to delete array elements in php are: 1. unset() function; 2. array_splice() function; 3. array_diff() function; 4. array_diff_key() function.

Specific method:

(Recommended tutorial: mysql tutorial)

Delete an element, And keep the original index 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 index of the array.

If you plan to rearrange the index (so that the index starts from 0 and is continuous), you can use the array_values ​​function:

$array = array_values($array);

Output

array(2) {
 [0]=>
 string(1) "a"
 [1]=>
 string(1) "c"
}

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
)

Delete multiple elements by value, keeping the index

Use the array_diff function, An 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 keep the index.

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 Keep the index.

Related recommendations: php training

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