PHP array_diff() Function

The array_diff () function in PHP compares array1 against other specified arrays and returns the values in array1 that are not present in any of the other arrays.

Syntax

array_diff(array$array1,array$array2[,array$...] )

Parameter

array1(required)- This parameter signifies the input array to compare from.

array2(required)- This parameter signifies the input array to compare against.

array3….(optional)- It represents more arrays to compare against

Return

This function returns an array containing all the entries from array1 that are not present in any of the other arrays. It returns null if all the values of array1 are present in other arrays.

Example 1

Output

array_diff(array$array1,array$array2[,array$...] )

 Array 1: 
 array (
  0 => 'aqua',
  1 => 'green',
  2 => 'red',
  3 => 'blue',
  4 => 'red',
 ) 
 Array 2: 
 array (
  0 => 'blue',
  1 => 'green',
  2 => 'yellow',
  3 => 'red',
 )
 Difference: 
 Array
 (
  [0] => aqua
 ) 

Example 2

  "Reema", 2 => "Akash", 3 => "Sukla", 4 =>"Varun",5=>"Mukta",6=>"Amar");
 //initializing array2
 $array2 = array(1 => "Reema", 2 => "Akash", 3 => "Tisha", 4 =>"Varun");
 //initializing array3
 $array3 = array(1 => "Rahul", 2 => "Akash", 3 => "Tisha", 4 =>"Varun");
 //computing the difference array1, array2 and array3
 $difference = array_diff($array1,$array2,$array3);
 //printing the difference containing all the entries from array1 that are not present in array2 and array3
 print_r($difference);
 ?> 

Output

Array
 (
  [3] => Sukla
  [5] => Mukta
  [6] => Amar
 ) 

Example 3

1,2=>2,3=>3,4=>4,5=>5,6=>6,7=>7,8=>8,9=>9,10=>10);
 //initializing array2 with odd number
 $array2 = array(1=>1,2=>3,3=>5,4=>7,5=>9);
 //computing the difference array1 and array2
 $difference = array_diff($array1,$array2);
 //printing the difference of the values
 print_r($difference);
 ?> 

Output

Array
 (
  [2] => 2
  [4] => 4
  [6] => 6
  [8] => 8
  [10] => 10
 ) 

Example 4

 "Reema",2=>"Rahul",3=>"ketan",4=>"Sashan");
 //initializing array2 with odd number
 $array2 = array(1=>"Reema",3=>"Rahul",67=>"ketan",14=>"Sashan");
 //computing the difference array1 and array2
 $differnce = array_diff($array1,$array2);
 //will return null as both the values are the same
 print_r($differnce);
 ?> 

Output

Array
 (
 )