WEB.JS/01.BASIC_JS

chapter03 : 형변환

GAWON 2023. 5. 19. 09:18 
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
	var a = true;
	var b = 100;
	var c = "Hello";
	var d = Math.sqrt(4);		// 제곱근
	var e = Math.sqrt(-4);		// NaN : Not a Number : 존재하지 않는 숫자

	document.write(a + "<br>");
	document.write(b + "<br>");
	document.write(c + "<br>");
	document.write(d + "<br>");
	document.write(e + "<br>");
	document.write("----------------<br/>");

	// 1. 숫자로 변환 : Number(값)
	document.write(Number(a) + "<br>");			// true == 1, false == 0
	document.write(Number(b) + "<br>");
	document.write(Number(c) + "<br>");			// "Hello"는 숫자 변환이 안되므로 NaN
	document.write(Number(d) + "<br>");
	document.write(Number(e) + "<br>");
	document.write("----------------<br/>");

	// 2. 문자열로 변환 : String(값)
	document.write(String(a) + "<br>");
	document.write(String(b) + "<br>");
	document.write(String(c) + "<br>");
	document.write(String(d) + "<br>");
	document.write(String(e) + "<br>");
	document.write("----------------<br/>");




</script>
</head>
<body>

</body>
</html>