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<head>
<meta charset="UTF-8" />
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<title>Document</title>
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<body>
<script>
// 1
// var๋ก ์ ์ธํ ๋ณ์๋ ์ ์๋ , ๋ฌธ์๋ ๋ค ์์ ์์ฌ๋ก ๋ฐ๊ฟ ์ ์๋ค.
var a = 1;
a = "test";
console.log(a + 1);
//2
// ==: ๋๋ฑ์ฐ์ฐ์, ===: ์ผ์น์ฐ์ฐ์
// ==: ๊ฐ(์๋ฏธ) ๋น๊ต, ===: ๊ฐ(์๋ฏธ) & ๋ฐ์ดํฐํ์
๋น๊ต
console.log(1 == 1); //true
console.log(1 == "1"); //true
console.log(1 === "1"); //false
console.log(undefined == null); //true
console.log(undefined === null); //false
console.log(1 == true); //true
console.log(1 === true); //false
//3
// ==: ์๋ฏธ ๋น๊ต, ===: ์๋ฏธ, ํ์
๋น๊ต
console.log(1 != "1"); //false
console.log(1 !== "1"); //true
//4
// ์กฐ๊ฑด๋ฌธ
if (true) {
console.log("result is true");
}
if (false) {
var age = prompt("๋์ด๋ฅผ ์
๋ ฅํด์ฃผ์ธ์.");
if (age === "25") {
alert("25 good bye!");
}
var id = prompt("id๋ฅผ ์
๋ ฅํด์ฃผ์ธ์.");
if (id == "sunakang") {
var pw = prompt("pw๋ฅผ ์
๋ ฅํด์ฃผ์ธ์.");
if (pw == "sunakang") {
alert("Hello, " + id);
} else {
alert("๋น๋ฐ๋ฒํธ๋ฅผ ๋ค์ ์
๋ ฅํด์ฃผ์ธ์.");
}
} else {
alert("๋๊ตฌ์ธ์?");
}
}
//5
// ๋ฐ๋ณต๋ฌธ
while (false) {
console.log("hi");
}
//6
// ํจ์
/**
* 1. ์ฌ์ฌ์ฉ์ฑ
* 2. ์ ์ง๋ณด์ ์ฉ์ด
* 3. ๊ฐ๋
์ฑ
**/
function numbering() {
var i = 0;
while (i < 5) {
document.write(i + "<br/>");
i++;
}
}
//numbering();
// ์ถ๋ ฅ - return
function get_member() {
return "suna"; //์ถ๋ ฅ๋๊ณ ๋
return "sun";
return "sunakang";
}
console.log(get_member());
// ์
๋ ฅ
// - ์ ๋ฌํ๋ ๊ฐ = ์ธ์(argument)
// - ์ ๋ฌ๋ฐ๋ ๋ณ์ = ๋งค๊ฐ๋ณ์, ํ๋ผ๋ฏธํฐ(parameter)
// value: ๋งค๊ฐ๋ณ์(parameter)
function get_argument(value) {
return value * 2;
}
// 100: ์ธ์(argument)
console.log(get_argument(100));
// ํจ์ ํํ2
var write_function = function write_function() {
return "fuction<br/>";
};
console.log(write_function);
// ํจ์ ํํ3 - ์ต๋ช
ํจ์, ์ ์์ ํธ์ถ์ ๋์์ ํจ
(function () {
console.log("suna");
})();
//7
// ๋ฐฐ์ด
var member = ["kang", 1, "suna"];
console.log(member[0] + " & " + member[1]);
function get_member2() {
return ["1", 2, 3.3];
}
var member2 = get_member2();
console.log(member2[0] + " & " + member2[1] + " & " + member2[2]);
var member3 = ["kang", "suna", "test"];
for (var i = 0; i < member3.length - 1; i++) {
console.log(member3[i].toUpperCase() + "<br/>");
}
var list = [1, 2, 3];
// push: ๊ผฌ๋ฆฌ์ ์ถ๊ฐ
list.push(4);
console.log(list);
// unshift: ๋จธ๋ฆฌ์ ์ถ๊ฐ
list.unshift(0);
console.log(list);
// concat: ์ธ์๋ก ์ ๋ฌํ์ฌ ๊ผฌ๋ฆฌ์ ์ถ๊ฐ
list = list.concat(5);
console.log(list);
// splice: 0๋ถํฐ 2๊น์ง๋ฅผ -1๋ก ๋ณ๊ฒฝ
list.splice(0, 3, -1);
console.log(list);
</script>
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