javascriptBasic/10_var.html at master · YoungjuneKim/javascriptBasic · GitHub

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<!DOCTYPE html>
<html lang="ko">
<head>
    <meta charset="UTF-8">
    <title>HTML Intro</title>
</head>

<script>
//Boolean, Number, String, Array, Object 5가지타입

console.log(a) ; //undefined
var a = 1 ;
console.log(a) ;

//console.log(b) ; //error
b = 2 ;          //전역객체 -> window.b =2
console.log("b:", b) ;
console.log("window.b : ", window.b) ;

var f1 = function() {
                c = 1 ; //window.c =1
                var c = 3; //이게 없으면 위에 c에 연산
                c++ ;
                console.log("f1 c : ", c) ;
                console.log("f1 window.c : ", window.c) ; //undefined
            } ;

f1() ;
console.log("window.c : ", window.c) ; //undefined

var d = 1 ;
var d = 2 ;
console.log("d:", d) ;

function f2() {
    var f = 10 ;
    g = 11 ;
}

f2() ;

//console.log("f:", f) ; //error
console.log("g:", g) ;
console.log("window.g:", window.g) ;

</script>

<body>
    <h1>https://developer.mozilla.org</h1>
    <h1>여러분을 환영합니다!!</h1>
</body>
</html>