- String -> int
- Integer.paseInt()
: static int parseInt(String s)
문자열을 입력받아 integer로 변환한 int 값을 리턴한다.
String str = "123";
int x = Integer.parseInt(str);
- Integer.valueOf()
: static int valueOf(String s)
문자열을 입력받아 Integer Object를 리턴한다.
String str = "123";
int x = Integer.valueOf(str);
그 외 타입들...
매개변수로는 숫자로 이루어진 문자만 가능하다.
Byte.parseByte();
Short.parseShort();
Integer.parseInt();
Long.parseLong();
Float.parseFloat();
Double.parseDouble();
- int -> Stirng
- Integer.toStirng()
- String.valueOf()
- int + ""
계산기 프로그램으로 parse 실습(String -> Double)
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="./ex05Action.jsp" method="post" >
<div>
x : <input type="text" name="x">
</div>
<div>
<select name="op">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select>
</div>
<div>
y : <input type="text" name="y">
</div>
<button type="submit">계산</button>
</form>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
String paramX = request.getParameter("x");
String paramY = request.getParameter("y");
String op = request.getParameter("op");
double x = Double.parseDouble(paramX);
double y = Double.parseDouble(paramY);
double result = 0;
if(op.equals("+")){
result = x + y;
} else if(op.equals("-")){
result = x - y;
} else if(op.equals("*")){
result = x * y;
} else if(op.equals("/")){
result = x / y;
} else{
%>
<div>잘못된 연산자를 입력하셨습니다.</div>
<%
}
%>
<div>result : <%=result%></div>
</body>
</html>
