How to use foreach in PHP
We can iterate over an array (or even objects) in PHP using the foreach construct. In this shot, we will see how to use this construct over arrays.
This construct is useful when we need to iterate without knowing the size of the array.
Syntax
foreach can be used in two ways:
foreach($array as $key => $value;
//OR
foreach($array as $value).
Let’s see the differences.
1.＄key => ＄value
If we specify the ＄key, we can view the specified key along with the elements. Otherwise, the
index of the element is shown alongside the element value.
This works with both one-dimensional and multi-dimensional arrays.
Let’s see an example:
<?php// first, we need to declare two array$arr1 = [1, 2, 3, 4, 5];$arr2 = ["key1" => 1,"key2" => 2,"key3" => 3,"key4" => 4,"key5" => 5,];// print the first arrayforeach($arr1 as $key => $value){echo $key . " => " . $value . "\n";}// print the second arrayforeach($arr2 as $key => $value){echo $key . " => " . $value . "\n";}
In the first case, we iterated over an array with numeric indexes. In the second case, we iterated over an array with key-value pairs.
2.＄value
If we omit the ＄key, we will only be able to see the value of the array.
The usage is similar to the previous one:
<?php// first, we need to declare two array$arr1 = [1, 2, 3, 4, 5];$arr2 = ["key1" => 1,"key2" => 2,"key3" => 3,"key4" => 4,"key5" => 5,];// print the first arrayforeach($arr1 as $value){echo $value . "\n";}echo "--\n";// print the second arrayforeach($arr2 as $value){echo $value . "\n";}
You can see that the output is the same since the arrays have the same values.
