php is associative array have key code example

Example 1: php key in array exists

<?php
$search_array = array('first' => null, 'second' => 4);

// returns false
isset($search_array['first']);

// returns true
array_key_exists('first', $search_array);
?>

Example 2: array key value php

<?php
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
foreach($age as $x=>$x_value)
  {
  echo "Key=" . $x . ", Value=" . $x_value;
  echo "<br>";
  }
?>