ArupSen · November 14, 2012 15:59
diff --git a/output_numbers.php b/output_numbers.php
 // To remove anything that is not a number:

 $output = preg_replace('/[^0-9]/', '', $input);
 /*
 Explanation:

 [0-9] matches any number between 0 and 9 inclusively.
 ^ negates a [] pattern.
 So, [^0-9] matches anything that is not a number, and since we're using preg_replace, they will be replaced by nothing '' (second argument of preg_replace).
 */
	// To remove anything that is not a number:

	$output = preg_replace('/[^0-9]/', '', $input);
	/*
	Explanation:

	[0-9] matches any number between 0 and 9 inclusively.
	^ negates a [] pattern.
	So, [^0-9] matches anything that is not a number, and since we're using preg_replace, they will be replaced by nothing '' (second argument of preg_replace).
	*/