Objects and Functions

Function Statement

: initially put in to memory, but have to invoke it for it to execute

함수 선언식은 항상 상단으로

show();
function show() {
	console.log('displayed!');
}

Function Expression( not hoisted )  

+ ( parameter ) = Immediately Invoked Function Expression(IIFE)

: A unit of code that results in a value

not initially put in to memory, when it hits this line it creates this function object on the fly.

It doesn't have to save to a variable

함수 표현식은 할당된 변수만 상단으로 Hoisting

show(); // <TypeError> show is not a function 
var show = function() {
	console.log('displayed!');
}

 

 

IIFE

var firstname = "John";

(function(name) {

var greeting = "Inside IIFE: hello";

console.log(greeting + ' ' + name);  >  Inside IIFE: hello John

}(firstname));

 

IIFEs and Safe Code

 

 

Arguments

: The parameters you pass to function

Javascript gives you a keyword of the same name which contains them all

 

by value(primitives) / by reference(all objects (including functions) 

equals operator sets up new memory space(new address)

 

 

'this'

 

 

Automatic Semicolon Insertion

 

Closure

 

 

 

 

First class functions & Closures

Everytime call a function it gets it own execution context. Any functions created inside of it will point that execution context

 

First Class Functions

: Everything you can do with other types you can do with functions.

Assign them to variables, pass them around, create them on the fly

 

Callback Function

: A function you give to another function, to be run when the other function is finished

  So the function you call, 'calls back' by calling the function you gave it when it finishes

 

call(), apply(), bind()  복습하기

Functional programming > Underscore Library

 

Function Currying

: Creating a copy of a function but with some preset parameters

  Very useful in mathematical situations