자바스크립트 변수선언방식(var,let,const)의 차이

자바스크립트에서는 변수선언방식이(var,let,const) 가 있다 

각각의 특징을 알려주겠다

 

var

중복선언가능

재할당가능

var title = 'book';
console.log(title); // book

var title = 'movie';
console.log(title); //movie

title = 'music';
console.log(title);//music

 

let

중복선언불가능

재할당가능

let title = 'book';
console.log(title); // book

let title = 'movie';
console.log(title); 
//Uncaught SyntaxError: Identifier 'title' has already been declared

title = 'music';
console.log(title);//music

 

const

중복선언불가능

재할당불가능

const title = 'book';
console.log(title); // book

const title = 'movie';
console.log(title); 
//Uncaught SyntaxError: Identifier 'title' has already been declared

title = 'music';
console.log(title);
//Uncaught TypeError: Assignment to constant variable