PHP foreach Loop
The foreach loop - Loops through a block of code for each element in an array.
The PHP foreach Loop
The foreach loop works only on arrays, and is used to loop through each key/value pair in an array.
Syntax
foreach [$array as$value] {
code to be executed;
}
For every loop iteration, the value of the current array element is assigned to $value and the array pointer is moved by one, until it reaches the last array element.
Examples
The following example will output the values of the given array [$colors]:
Example
Try it Yourself »
The following example will output both the keys and the values of the given array [$age]:
Example
Try it Yourself »
You will learn more about arrays in the PHP Arrays chapter.
In this tutorial, we look at the PHP foreach[] loop. We also look at how to use it while working with an indexed or associative array.
Table of Contents - PHP foreach:
- What is foreach[]?
- Code and Explanation
- Indexed arrays
- Associative arrays
- Closing thoughts
What is foreach in PHP?
The foreach[] method is used to loop through the elements in an indexed or associative array. It can also be used to iterate over objects. This allows you to run blocks of code for each element.
Syntax of PHP foreach[]:
The foreach[] method has two syntaxes, one for each type of array.
The syntax for indexed arrays is as given in the following code block:
foreach [iterable as $value]
statement
The syntax for associative arrays:
foreach [iterable as $key => $value]
statement
Here, “Iterable” is the required parameter. It is the array or the variable containing the array. “$value” is a variable that stores the current element in each iteration.
Associated array, uses keys and values, and hence the $key & $values in the second syntax represent the same accordingly.
Code & Explanation:
In this section, we first look at
how the foreach[] function works on an indexed array followed by which we look at it’s working on an associative array.
PHP Foreach[] on Indexed arrays:
The output of the above code snippet would be:
Hire
Top
Freelance
developers
PHP Foreach[] on an Associative array:
The output of the above code snippet would be:
name: Eric
email: [email protected]
age: 22
gender: male
Now let’s look at a case where we pass a second argument.
As you can see the key and the values of the associative
array were printed. Additionally, we replaced “=>” with a “:” to make it more readable.
Closing thoughts:
The foreach[] method would return an error in case you use it on variables with a different data type. Additionally, the foreach[] method does not modify the values of the internal pointer.
Once you have understood the working to the foreach[] method try working with the for loop.
[PHP 4, PHP 5, PHP 7, PHP 8]
The foreach construct provides an easy way to iterate over arrays. foreach works only on arrays and objects, and will issue an error when you try to use it on a variable with a different data type or an uninitialized variable. There are two syntaxes:
foreach [iterable_expression as $value]
statement
foreach [iterable_expression as $key => $value]
statement
The first form traverses the iterable given by iterable_expression. On each iteration, the value of the current element is assigned to
$value.
The second form will additionally assign the current element's key to the $key variable on each iteration.
Note that foreach does not modify the internal array pointer, which is used by functions such as current[] and key[].
It is possible to customize object iteration.
In order to be able to directly modify array elements within the loop precede $value with &. In that case the value will be assigned by reference.
Warning
Reference of a $value and the last array element remain even after
the foreach loop. It is recommended to destroy it by unset[]. Otherwise you will experience the following behavior:
It is possible to iterate a constant array's value by reference:
Note:
foreachdoes not support the ability to suppress error messages using@.
Some more examples to demonstrate usage:
Unpacking nested arrays with list[]
[PHP 5 >= 5.5.0, PHP 7, PHP 8]
It is possible to iterate over an array of arrays and unpack the nested array into loop variables by providing a list[] as the value.
For example:
The above example will output:
You can provide fewer elements in the list[] than there are in the nested array, in which case the leftover array values will be ignored:
The above example will output:
A notice will be generated if there aren't enough array elements to fill the list[]:
The above example will output:
Notice: Undefined offset: 2 in example.php on line 7 A: 1; B: 2; C: Notice: Undefined offset: 2 in example.php on line 7 A: 3; B: 4; C:
Sanusi Hassan ¶
1 day ago
destructure array elements
you can unpac nested array elements using the following