Function selfiexecuting in var

Question

Can somebody tell me, can I in javascript declare a function into var and execute it in the same experession(program-line)?

var tmp = 0,
a = function() {
    ++tmp; /*rest of code*/
};
a();
console.log(tmp);

What happens if you stick that into the console? Does it work? — putvande, Jun 02 '17 at 12:20
I got 1, i want to get 2: once incrementation in function initialization and next one in function execute — Kamczatka, Jun 02 '17 at 12:26
@Kamczatka Why not just call it immediately after the declaration? — Bergi, Jun 02 '17 at 13:56

score 1 · Answer 1 · answered Jun 02 '17 at 12:31

if you surround a function declaration with parentesis you get an expression. an assigment is also an expression (is evaluated as the value assigned) and you can leverage this fact to obtains your result.

var tmp = 0, a;
(a = function() { ++tmp;})();
a();
console.log(tmp);

Said that, to me, I wouldn't like to have to read code like this. It is prone to errors and misinterpretation.

Function selfiexecuting in var

1 Answers1