숫자 1개를 입력받아 합산하기
<title>숫자를 넣어보자</title>
<script type="text/javascript">
function chk() {
if (!frm.num.value) {
alert("숫자 입력하세요");
frm.num.focus();
return false;
}
if (isNaN(frm.num.value)) {
alert("숫자몰라! 혹시 바보아냐?");
frm.num.focus();
frm.num.value="";
return false;
}
return true;
}
</script>
</head>
<body>
<h2>숫자 1개 입력 하세요</h2>
<form action="Sum" name="frm" onsubmit="return chk()">
숫자 : <input type="text" name="num"><p>
<input type="submit" value="확인">
</form>
</body>
숫자를 넣을 html작성
public class Sum extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int num=Integer.parseInt(request.getParameter("num"));
response.setContentType("text/html;charset=utf-8");
int sum=0;
for (int i =1 ; i <= num; i++) {
sum += i;
}
PrintWriter out = response.getWriter();
out.println("<html><body>");
out.println("<h2>1에서 "+num+"까지 합 : "+sum +"</h2>");
out.println("</body></html>");
out.close();
}
for문을 이용하여 한자리 숫자를 합산