Merge two arrays keeping original keys in PHP

0 0 1 minute read

Problem: How to merge two arrays while keeping keys instead of reindexing in PHP?
Solution: This can be achieved in two ways which are by using + operator and by using inbuilt functions.

Method 1: Using + operator.
Example :

<?php 
$array1 = array( 
         1 =>'Geeks', 
         2 =>'For', 
         3 =>'Geeks'
          ); 
  
 $array2 = array( 
          4 => 'A', 
          5 => 'Computer', 
          6 => 'Science', 
          7 => 'Portal', 
          8 => 'For', 
          9 => 'Geeks'
         ); 
  
  $merged_array = $array1 + $array2; 
  var_dump ($merged_array); 
?> 

Output:

array(9) {
  [1]=>
  string(5) "Geeks"
  [2]=>
  string(3) "For"
  [3]=>
  string(5) "Geeks"
  [4]=>
  string(1) "A"
  [5]=>
  string(8) "Computer"
  [6]=>
  string(7) "Science"
  [7]=>
  string(6) "Portal"
  [8]=>
  string(3) "For"
  [9]=>
  string(5) "Geeks"
}

Method 2: Using inbuilt function array_replace() function.
Example :

<?php 
$array1 = array( 
         1 =>'Geeks', 
         2 =>'For', 
         3 =>'Geeks'
          ); 
  
 $array2 = array( 
          4 => 'A', 
          5 => 'Computer', 
          6 => 'Science', 
          7 => 'Portal', 
          8 => 'For', 
          9 => 'Geeks'
         ); 
  
  $merged_array = array_replace($array1, $array2); 
  var_dump ($merged_array); 
?> 

Output:

array(9) {
  [1]=>
  string(5) "Geeks"
  [2]=>
  string(3) "For"
  [3]=>
  string(5) "Geeks"
  [4]=>
  string(1) "A"
  [5]=>
  string(8) "Computer"
  [6]=>
  string(7) "Science"
  [7]=>
  string(6) "Portal"
  [8]=>
  string(3) "For"
  [9]=>
  string(5) "Geeks"
}

Reference :http://php.net/manual/en/function.array-replace.php