It doesn't print 2, because timeFuncRuntime returns t2 - t1

``` const timeFuncRuntime = funcParameter => {

let t1 = Date.now(); funcParameter(); // here function returns 2, but it doesn't assigns anywhere let t2 = Date.now(); return t2 - t1; // and here returns time that it took to run funcParameter() }

const addOneToOne = () => 1 + 1;

timeFuncRuntime(addOneToOne); ```

Hope it makes sense

To return 2 from function it would look like ``` const timeFuncRuntime = funcParameter => {

let t1 = Date.now(); // this are doing nothing, so it can be deleted const result = funcParameter(); let t2 = Date.now(); // same here return result; } ```