Greatest common factor

[insanepenguin]

function getGCF($a, $b){
if($b == 0){
return $a;	
} else {
	return getGCF($b, $a % $b);	
}
}

 

Can someone explain how the 'returnGCF' function works, I know for example the greatest common factor of 6, 2 is 2 because 2 is the greatest number to go in to 6 and itself.

 

I'm just a bit confused about the modulus % part: 2, 6 % 2 = 2 any explanations to help a newbie welcome!

[Mchl]

6 % 2 = 0 actually. Modulus will give you a remainder from division of two numbers. For example, when youdivide 10 by 3, you can 'fit' three 3s into 10, and there will be 1 left. Hence 10 % 3 = 1

[MadTechie]

modulus gives you the remainder of a division

for example

100 % 24 = 4

24 goes into 100, 4 times but then has 4 remaining

100 - 24 = 76

76 - 24 = 52

52 - 24 = 28

28 - 24 = 4