Today I was writing some code in which I wanted to modify the values of an array within a for-loop. The obvious solution would be to use the key to modify the value but there is actually another way of doing it:
$arr = array(1,2,3,4,5);
foreach ($arr as &$value) {
$value = $value * $value;
}
print_r($arr);
The above code will actually go through the array of integers 1 to 5 and change the array to be the squares of those values. The output is as follows:
Array
(
[0] => 1
[1] => 4
[2] => 9
[3] => 16
[4] => 25
)
This works because placing the ampersand in front of the $value makes the variable refer to the actual value within the array and updating it will update the value within the array.
