How to reverse the position of keys and values ​​in an array in PHP? (code example)

In PHP, we can use the built-in function array_flip() function to reverse the positions of keys and values ​​in the exchange array. The following article will show you how to use the array_flip() function. I hope it will be useful to everyone. help.

PHP array_flip() function

array_flip() function is used to reverse/exchange arrays The key name and the corresponding associated key value, and vice versa. [Video tutorial recommendation: PHP tutorial]

Note: We must remember that the values ​​of the array must be valid keys, that is, they must be integers or strings. If a value is of the wrong type, a warning will be thrown and the associated key/value pair will not be included in the result.

Basic sentence pattern:

array_flip($array);

Parameters: This function only accepts one parameter $array, which is used to specify the key/value pair to be reversed Array to rotate.

Return value: array_flip() function will return the reversed array when the reversal is successful; if the reversal fails, it will return NULL.

How to reverse the keys and values ​​in an array?

The following is a simple code example to see how the array_flip() function reverses the key names and corresponding associated key values ​​​​in the array.

Example 1:

<?php 
header("content-type:text/html;charset=utf-8");    
$array = array("0" => "php", "1" => "java",  
               "2" => "python", "3" => "mysql"); 
echo ("反转前：");
var_dump($array);
$result=array_flip($array);
echo ("反转后：");
var_dump($result);
  
?>

Output:

Example 2:

<?php 
header("content-type:text/html;charset=utf-8");  
$array = array("aakash" => "rani", "rishav" => "sristi",  
               "gaurav" => "riya", "laxman" => "rani"); 
echo ("反转前：");
var_dump($array);
$result=array_flip($array);
echo ("反转后：");
var_dump($result);
?>

Output:

Note: If the associated key values ​​corresponding to multiple key names are the same, the last key name will be used as its value during conversion, and all others will be lost.

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