PHP in_array() Function

The PHP in_array() function checks if a value exists in an array. The function returns true if the value is found in the array, else returns false. The comparison is done in a case-sensitive manner.

Syntax

in_array(search, array, strict)

Parameters

`search`	`Required.` Specify the searched value.
`array`	`Required.` Specify the array to search.
`strict`	`Optional.` If this parameter is set to true then the in_array() function will also check the types of the searched value in the array.

Return Value

Returns true if the value is found in the array, else returns false.

Exceptions

NA.

Example:

The example below shows the usage of in_array() function.

<?php
$Arr = array("Red", "Green", "Blue");

//checking "Blue" in the array
if(in_array("Blue", $Arr)){
  echo "Blue is found.\n";
} else {
  echo "Blue is not found.\n";
}

//checking "red" in the array
if(in_array("red", $Arr)){
  echo "red is found.\n";
} else {
  echo "red is not found because case is not matched.\n";
}
?>

The output of the above code will be:

Blue is found.
red is not found because case is not matched.

Example: using strict parameter

When the strict parameter is set to true, type of the value is also checked. Consider the example below:

<?php
$Arr = array("1.5", 1.6, 1.7, 1.8);

//checking 1.5 in the array
if(in_array(1.5, $Arr)){
  echo "1.5 is found.\n";
} else {
  echo "1.5 is not found.\n";
}

//checking 1.5 in the array using strict parameter
if(in_array(1.5, $Arr, true)){
  echo "1.5 is found.\n";
} else {
  echo "1.5 is not found because type is not matched.\n";
}
?>

The output of the above code will be:

1.5 is found.
1.5 is not found because type is not matched.

Example: Searching array

In the example below, an array is searched in an array.

<?php
$Arr = array(array(1, 2, 3), array(10, 20));

//checking array(1, 2) in the array
if(in_array(array(1, 2), $Arr)){
  echo "array(1, 2) is found.\n";
} else {
  echo "array(1, 2) is not found.\n";
}

//checking array(1, 2, 3) in the array
if(in_array(array(1, 2, 3), $Arr)){
  echo "array(1, 2, 3) is found.\n";
} else {
  echo "array(1, 2, 3) is not found.\n";
}
?>

The output of the above code will be:

array(1, 2) is not found.
array(1, 2, 3) is found.

❮ PHP Array Reference