<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
th{
background-color: #A9D0F5;
}
td{
text-align: center;
}
</style>
</head>
<body>
<h1>배열의 연산</h1>
<table border="1" style="width: 30%" id="tb">
<col style="width: 50">
<col style="width: 80">
<col style="width: 80">
<col style="width: 100">
<tr>
<th>첨자</th>
<th>a</th>
<th>b</th>
<th>a x b 를 계산</th>
</tr>
<tr>
<th>0</th>
<td>5</td>
<td>33</td>
<td><input type="button" onclick="func(1)" value="계산결과"></td>
</tr>
<tr>
<th>1</th>
<td>12</td>
<td>14</td>
<td><input type="button" onclick="func(2)" value="계산결과"></td>
</tr>
<tr>
<th>2</th>
<td>18</td>
<td>65</td>
<td><input type="button" onclick="func(3)" value="계산결과"></td>
</tr>
</table>
<script type="text/javascript">
// rows[]와 cells[]로 셀에 접근하기
function func( num ) {
var n1 = document.getElementById("tb").rows[num].cells[1].innerHTML;
var n2 = document.getElementById("tb").rows[num].cells[2].innerHTML;
var result = n1 * n2;
alert(result);
}
</script>
</body>
</html>