• ← Which

While

WMA link

While[test, body]

evaluates body as long as test evaluates to True.

While[test]

runs the loop without any body.

Compute the GCD of two numbers:

• • {a, b} = {27, 6};

• • While[b != 0, {a, b} = {b, Mod[a, b]}];

• • a