Ch 4 Functions First is a little confusing

[davidbkemp]

You state that functions are hoisted before variables, and yet these functions can refer to variables defined in the same scope. Is it simply the case that the variables will be defined by the time the function is actually called, or is it that all the variable and function names are hoisted together, then the functions defined, and then the remainder of the code executed?

[getify]

I think the proper way to think about it is: functions are hoisted first and then variables, but a function execution (as with any other sort of statement) always happens after both have been declared, which means that a function referencing a variable will find it by the time the function is executed.

[davidbkemp]

OK, I guess it is a fairly minor distinction anyway. Keep up the great work!

[getify]

Thanks! :)

[muradsofiyev]

function foo() {
    console.log( foo );
}
var foo;


foo()

But what is happened in there? If functions are hoisted first and then variables we can't call foo like function but we can

[getify]

var foo; does not do the same thing as var foo = undefined;. The former creates a variable that is auto-initialized at the top of the scope. The latter has as assigment expression that happens during runtime at that point in the code.