how to concnate two array in php code example

Example 1: php merge 2 arrays

<?php
  $array1 = [
      "color" => "green"
  ];
  $array2 = [
      "color" => "red", 
      "color" => "blue"
  ];
  $result = array_merge($array1, $array2);
?>

// $result
[
    "color" => "green"
    "color" => "red", 
    "color" => "blue"
]

Example 2: merge array in php

$a1=array("red","green");
$a2=array("blue","green","yellow");
print_r(array_merge($a1,$a2));