3 Ways to Loop Through an Array in PHP

Looping through arrays to display data or to do something with data elements is a common task in PHP. In this post, I will introduce 3 ways to loop through an array.

Use foreach

Example array:

$phoneBrands = array(
	'apple' => array('Apple', 'iPhone'),
	'samsung' => array('Samsung', 'Galaxy Note'),
	'huawei' => array('Huawei', 'P30'),
	'xiaomi' => array('Xiaomi', 'Redmi Note 7'),
);

The foreach construct is the most common way to iterate over arrays.

//with $key: current element's key is assigned to variable $key
foreach($phoneBrands as $key => $brand){
	var_dump($key);
	var_dump($brand);
}

Result

string(5) "apple"
array(2) { [0]=> string(5) "Apple" [1]=> string(6) "iPhone" } 
string(5) "samsung" 
array(2) { [0]=> string(7) "Samsung" [1]=> string(11) "Galaxy Note" } 
string(5) "hauwei" 
array(2) { [0]=> string(6) "Huawei" [1]=> string(3) "P30" } 
string(5) "xiaomi" 
array(2) { [0]=> string(6) "Xiaomi" [1]=> string(12) "Redmi Note 7" }  

//without $key
foreach($phoneBrands as $brand){
	var_dump($brand);
}

Result:

array(2) { [0]=> string(5) "Apple" [1]=> string(6) "iPhone" } 
array(2) { [0]=> string(7) "Samsung" [1]=> string(11) "Galaxy Note" } 
array(2) { [0]=> string(6) "Huawei" [1]=> string(3) "P30" } 
array(2) { [0]=> string(6) "Xiaomi" [1]=> string(12) "Redmi Note 7" }  

Use for loop

$phoneBrands = array(
	array('Apple', 'iPhone'),
	array('Samsung', 'Galaxy Note'),
	array('Huawei', 'P30'),
	array('Xiaomi', 'Redmi Note 7'),
);
for ($i = 0; $i < count($phoneBrands); $i++) {	
    echo $phoneBrands[$i][0].' - '.$phoneBrands[$i][1].'<br>';
}

Result

Apple - iPhone
Samsung - Galaxy Note
Huawei - P30
Xiaomi - Redmi Note 7 

Use array_map()

array_map() function applies the callback to the elements of the given arrays. It is not a common way to loop through data but can be used to manipulate data in an array in some cases.

$phoneBrands = array(
	array('Apple', 'iPad'),
	array('Samsung', 'Galaxy S'),
	array('Huawei', 'P40'),
	array('Xiaomi', 'Mi Note'),
);
array_map('displayBrand', $phoneBrands);
function displayBrand($brand){
	echo $brand[0].' has '.$brand[1].'<br>';
}

Result

Apple has iPad
Samsung has Galaxy S
Huawei has P40
Xiaomi has Mi Note