array_flip

array array_flip(array values) 

Transposes the keys and values of an array.

Returns:

Associative array; FALSE if given an invalid argument

Description:

array_flip() converts the keys of an array into values and the values into keys, in effect transposing the keys and values of the array. This works for both indexed arrays and associative arrays.

If values contains multiple elements with the same value—which would cause the resulting array to have multiple identical keys—only the value of the last of these duplicates is used, and previous elements are lost.

Version:

PHP 4 since 4.0b4

Example:

Transpose the keys and values of an array

$fruits = array( 'a' => 'apple', 
                 'b' => 'banana', 
                 'c' => 'carrot', 
                 'd' => 'dachshund'); 
while(list($key,$val) = each($fruits)) {
    print("Key: $key -- Vaue: $val\n"); 
} 
$flipped = array_flip($fruits); 
while(list($key,$val) = each($flipped)) {
    print("Key: $key -- Value: $val\n"); 
} 

Output: 
Key: a -- Value: apple 
Key: b -- Value: banana 
Key: c -- Value: carrot 
Key: d -- Value: dachshund 
Key: apple -- Value: a 
Key: banana -- Value: b 
Key: carrot -- Value: c 
Key: dachshund -- Value: d