Why these brackets?

Question

Without the last pair of brackets the log won't show. Why?

var getReady = function() {
log('Ready for action');
}();

Answer 1

Because you use an anonyme function...

When you declare a function, you write:

function functionName() {
/* code of your function */
}

This is the same, in fact, that:

functionName = function() {
/* code */
}

Which assign the function to the variable "functionName"...
Well, to call it, in the two case ( because we keep the same name ), you do:

functionName();

So, in your code, you assign at the variable getReady, the value returned by execution of a function without name: you declare it, and execute it once, just after have declared it ( and there is no more way to call it a second time in this case -- sometimes, you declare anonymized function, without explicit assignment to a variable, but you register it even, like if passing to a function, which provide an implicit assignement to the attribute who's a function variable )

Answer 2

About the not-question of the log() function: nothing indicates that it's not a custom function, making go know what ^^

Answer 3

if you leave the last brackets it will just declare a function if you put last brackets too it calls the function itself

Answer 4

@Seiss K said "brackets" but context shows implicitly it was meaning "parenthesis" ;)

Answer 5

if u don't place brackets it stores tha function in that variable
ex: var m1 = function(){----};// function stored as an object in m1
m1();// this executes above function

if u place the brackets it executes the function and store the output value of that function

ex: var m1 = function(a,b) { return a+b;}(2,3);
alert(m1);// output is 5 here
here we are creating anonymous function with param's and passing 2,3 as parameters. that function return value stored in m1.

Answer 6

I am not sure but maybe you should type 'console.log' instead of just 'log'.
I have absolutly no idea what the last parenthesis are about

Answer 7

Thats it. Console.log() not lo()

Answer 8

now, that's a good answer! Thumbs up for visph!

Answer 9

the brackets r used for declaring a block of code

Answer 10

Because you need to "call" function execution. Eather with some parameter inside brackets or empty brackets if you don't have parameter...