How to use in_array() function in PHP

To check a variable exists in array you can use in_array() function:

Syntax: bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )

Parameters

needle

The searched value.

Note:

If needle is a string, the comparison is done in a case-sensitive manner.

haystack

The array.

strict

If the third parameter strict is set to TRUE then the in_array() function will also check the types of the needle in the haystack.

Return Values

Returns TRUE if needle is found in the array, FALSE otherwise.   

Example #1:

<?php
$fruit = array("apple", "banana", "orange");
if (in_array("apple", $fruit)) {
    echo "apple exist in $fruit array";
}
if (!in_array("iphone", $fruit)) {
    echo "iphone not exist in $fruit array";
}?>

Example #2:

<?php
$fruit = array("1", "2", "4","7");
if (in_array("1", $fruit)) {
    echo "Yes";
}

else

{

    echo "No";

}
?>

Example check array in array:

<?php
$a = array(array('a', 'e'), array('c', 'b'), 'd');

if (in_array(array('a', 'e'), $a)) {
    echo "Found";
}
else

{

    echo "Not found";

}
if (in_array(array('f', 'i'), $a)) {
    echo "Yes";
}

else

{

    echo "No";

}

if (in_array('d', $a)) {
    echo "'d' was found";
}?>