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.