how to check which array index has this element in php code example

Example 1: get index of element in array php

$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');

$key = array_search('green', $array); // $key = 2;
$key = array_search('red', $array);   // $key = 1;

Example 2: php array index exists

<?php
$array1=array("Orange" => 100, "Apple" => 200, "Banana" => 300, "Cherry" => 400);
if (array_key_exists("Banana",$array1))
{
echo "Array Key exists...";
}
else
{
echo "Array Key does not exist...";
}
?>