Basic JavaScript variable definition

Question

Coming from Python, learning JavaScript:

var test = 1;
var test2 = function(arg) {console.log(arg);};

When I execute var test3 = test2(test); in console, I get as a response:

undefined
1

But when I re-enter test3 or console.log(test3) I'm getting the undefined response inestead of 1. I tried to return value in function instead:

var test2 = function(arg) {return(console.log(arg));};

and

var test2 = function(arg) { var text = console.log(arg); return text;};

But I'm still getting the same response. How to 'bind' result of the function test2 to variable test3?

Thanks.

You're actually getting the result, but the default return value for any function in javascript is undefined, and that goes for console.log() as well. — adeneo
– adeneo, Commented Jul 15, 2014 at 16:34
Because the function does not have a value. To add one use return. For example: function(arg) {console.log(arg); return arg;} — Spencer Wieczorek
– Spencer Wieczorek, Commented Jul 15, 2014 at 16:35

parchment · Accepted Answer · 2014-07-15 16:32:50Z

1

console.log returns undefined.

var test2 = function(arg) { 
    var text = console.log(arg); // text === undefined
    return text;
}; // returns undefined

// Then ...

var test3 = test2(test); // test3 === undefined

answered Jul 15, 2014 at 16:32

parchment

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bevacqua · Accepted Answer · 2014-07-15 16:32:25Z

1

console.log always returns undefined

If you did return arg instead of returning what console.log returns, then you'd be good.

answered Jul 15, 2014 at 16:32

bevacqua

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Benjamin Trent · Accepted Answer · 2014-07-15 16:33:06Z

1

You are not setting test3 to anything. Console.log does not return anything(except undefined).

If you want to set it to the value of arg, just return the value itself.

answered Jul 15, 2014 at 16:33

Benjamin Trent

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