gugudan6.html

<!DOCTYPE html>
<html lang="ko">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
    <h1>반복문을 사용한 구구단 연습(for문)</h1>
    출력할 단 수: <input type="text" id="num">
    <button onclick="runGugudan()">확인</button>

    <script>
        function runGugudan() {
            var strN = document.getElementById("num").value
            var n = Number(strN);
            document.write("<h2>구구단" + n + "단</h2>")
            for (var i = 1; i <= 9; i++) {
                document.write(n + " * " + i + " = " + n * i + "<br/>");
            }    
        }
    </script>    
</body>
</html>