Javascript challenge - How to call a function such that it returns 8?

Question

Long time ago I saw a Javascript challenge, I do not remember where, but now I am trying to solve it. Until now, I do not know how to proceed.

I have this function and I have to make a call such that it returns 8:

function foo(a, b){
    b(function(){
        return a + a;
    });
}

Since foo does not return anything, is it possible to make the call I need? or it is just a tricky question?

depends on what you precisely mean with *"make a call such that it returns 8"*. I think the precise form of the original question is important here. — Denys Séguret, Mar 12 '14 at 15:54

score 0 · Accepted Answer · answered Mar 12 '14 at 15:59

0

If by "return" you mean alert or log it somewhere it is easy as:

foo(4, function(fn){
   console.log(fn());
});

Or even ignoring the input:

foo('bar', function(){
   console.log(8);
});

answered Mar 12 '14 at 15:59

qwertynl

Thanks, I will accept you answer since given the comments it is not possible to actually return something. – Miguel Jiménez Mar 12 '14 at 16:06
Although the second example is not what I was looking for. – Miguel Jiménez Mar 12 '14 at 16:08

score 0 · Answer 2 · answered Mar 12 '14 at 16:13

0

You can do this :

var r = foo(foo(0, function(){ foo = function(){ return 8 } }));

This gives to r the returned value which is 8.

answered Mar 12 '14 at 16:13

Denys Séguret

When I execute your code chrome says: "TypeError: undefined is not a function" – Miguel Jiménez Mar 13 '14 at 04:02

2 Answers2