php array get keys code example

Example 1: php all keys in array

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

$keys = array_keys($array);		// return array
$values = array_values($array);	// return array
?>

Example 2: get key of value array php

<?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 3: php keys of array

$array = array(0 => 100, "cor" => "vermelho");
print_r(array_keys($array));

$array = array("azul", "vermelho", "verde", "azul", "azul");
print_r(array_keys($array, "azul"));

$array = array("cor"     => array("azul", "vermelho", "verde"),
               "tamanho" => array("pequeno", "medio", "grande"));
print_r(array_keys($array));

Example 4: 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>";
  }
?>

Example 5: get key of array element php

$people = array(
  2 => array(
    'name' => 'John',
    'fav_color' => 'green'
  ),
  5=> array(
    'name' => 'Samuel',
    'fav_color' => 'blue'
  ));
$found_key = array_search('blue', array_column($people, 'fav_color'));

Example 6: php get array key

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name = current($array)) {
    if ($fruit_name == 'apple') {
        echo key($array).'<br />';
    }
    next($array);
}
?>