JavaScript Tutorial/Math/round
Math.round()
Syntax
math.round(num)
Rounding a number to an integer
<html>
<head>
<title>Rounding a number to an integer</title>
<script type="text/javascript" language="javascript">
<!-- //
function f(){
var num1 = 0.3;
var num2 = 0.1;
var result ;
result = num1 / num2;
document.write(Math.round(result));
}
// -->
</script>
</head>
<body onload="f()">
</body>
</html>
Use Math.round to calculate area
<html>
<head>
<title>A Simple Page</title>
<script language="JavaScript">
<!--
function calcArea()
{
inpRadius = 3;
alert(Math.round(Math.PI * ((inpRadius)*(inpRadius))));
}
function calcPeri()
{
inpRadius = 3;
alert(Math.round(2 * Math.PI * (inpRadius)));
}
function calcVol()
{
inpRadius = 3;
alert(Math.round(Math.PI * ((inpRadius)*(inpRadius)*(inpRadius)) * (4/3)));
}
// -->
</script>
</head>
<body>
<h1>All about Circles and Spheres!</h1>
<P>Click <input type="button" value="HERE" onclick="calcArea();"> to calculate circle area!</p>
<br>
<P>Click <input type="button" value="HERE" onclick="calcPeri();"> to calculate circle perimeter!</p>
<br>
<P>Click <input type="button" value="HERE" onclick="calcVol();"> to calculate sphere volume!</p>
</body>
</html>