PHP array_flip() function

PHP array_flip() function

The array_flip() function in PHP exchanges all keys with their associated values in an array and returns an array in flip order.

If the specified value has several occurrences, the latest key will be used as its value, and all others will be lost.

Syntax

array_flip ( array $array )

Parameter

array(required)- This parameter represents an input array of key/value pairs to be flipped.

Return

This function returns an array in flip order on success or returns NULL on failure.

Example 1

Output

Original array: 
 Array
 (
     [0] => India
     [1] => China
     [2] => Japan
     [3] => Sri Lanka
 ) 
  Flipped array: 
 Array
 (
     [India] => 0
     [China] => 1 
     [Japan] => 2
     [Sri Lanka] => 3
 ) 

Example 2

"apple", "g"=>"grapes", "b"=>"berry", "s"=>"Strawberry");
 echo("Original array: \n");
 print_r($input_array);
 //flipping the array keys and values
 $flipped_array = array_flip($input_array); 
 echo("\n Flipped array: \n");
 print_r($flipped_array);
 ?> 

Output

Original array: 
 Array
 (
     [a] => apple
     [g] => grapes
     [b] => berry
     [s] => Strawberry 
 )
  Flipped array: 
 Array
 (
     [apple] => a
     [grapes] => g
     [berry] => b 
     [Strawberry] => s
 ) 

Example 3

"A", "g"=>"G", "b"=>"B","s"=>"S");
 echo("Original array: \n");
 print_r($input_array);
 //flipping the array keys and values
 $flipped_array = array_flip($input_array); 
 echo("\n Flipped array: \n");
 print_r($flipped_array);
 ?> 

Output

Original array: 
 Array
 (
     [a] => A
     [g] => G
     [b] => B
     [s] => S 
 )
  Flipped array: 
 Array
 (
     [A] => a
     [G] => g
     [B] => b 
     [S] => s
 ) 

Example 4

"A", "g","G", "b","B");
 echo("Original array: \n");
 print_r($input_array);
 //flipping the array keys and values
 $flipped_array = array_flip($input_array); 
 echo("\n Flipped array: \n");
 print_r($flipped_array);
 ?> 

Output

Original array: 
 Array
 (
     [a] => A
     [0] => g
     [1] => G
     [2] => b
     [3] => B 
 )
  Flipped array: 
 Array
 (
     [A] => a
     [g] => 0
     [G] => 1 
     [b] => 2
     [B] => 3
 )