<%@ 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>
<%
//1부터 n까지의 합 //다시 1번 창에 보내기
String n = request.getParameter("nvalue");
if(!n.equals("")){
int value = Integer.parseInt(request.getParameter("nvalue"));
int sum=0;
for(int i=0;i<value+1;i++){
sum += i;
}
//System.out.println(sum);
request.setAttribute("value", value);
request.setAttribute("sum", sum);
}else{ //공백이면(자바스크립트로도 함)
request.setAttribute("sum", 0);
}
//System.out.println(value);
request.getRequestDispatcher("20210526_01_asum.jsp").forward(request, response);
%>
</body>
</html>