How to unshorten this js code

Question

I was trying to understand code of this Tic-Tac-Toe (30 lines of code) game and encountered with this strange for me notation of js.

I know that this is shortened version of if-statement, but don't know exactly how to convert it.

Thanks in advance.

Read up on the [ternary operator](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Conditional_Operator) (AKA the conditional operator). — nnnnnn, Feb 08 '16 at 22:08
Got to love the arrogance of the comments... The second one is essentially a nested `if` statement. In case that was the confusing bit as you said you understand that it's a shorthand if statement. — ste2425, Feb 08 '16 at 22:11
I have already read that this is ternary operator, thanks, but how to translate second if-statement with function? — Marian Petruk, Feb 08 '16 at 22:12
You'd evaluate the inner ternary first `(role == 'player') ? ai() : null` and the result becomes part of the outer ternary — j08691, Feb 08 '16 at 22:15

score 3 · Accepted Answer · edited Feb 08 '16 at 23:43

3

This is the ternary operator in javascript.

t[id] ? ai() : move(id, 'ai');

Translates to:

if (t[id])
    ai();
else
    move(id, 'ai');

And !checkEnd() ? (role == 'player') ? ai() : null : reset() to:

if (!checkEnd())
    if (role == 'player')
        ai();
    else
        ;
else
    reset();

edited Feb 08 '16 at 23:43

Marian Petruk

answered Feb 08 '16 at 22:07

Idos

thanks, and how second with function will be? – Marian Petruk Feb 08 '16 at 22:09
1

I will edit with that shortly, but I think you can deduce that from the first one – Idos Feb 08 '16 at 22:10
1

this second was confusing to me. Thanks for the answer. – Marian Petruk Feb 08 '16 at 22:15

score 0 · Answer 2 · answered Feb 08 '16 at 22:07

0

That is called a ternary operator.

Check this from MDN. They have good info if you're starting. And this one from MSDN

Simply put,

condition ?  expression if true : expression if false

answered Feb 08 '16 at 22:07

mugabits

2 Answers2