toExponential()Number对象的函数返回一个以指数表示形式表示数字对象的字符串。
其语法如下
var num=77.1234;
num.toExponential('0xF', 16);<html>
<head>
<title>JavaScript Example</title>
</head>
<body>
<script type="text/javascript">
var num = 77.1234;
document.write( num.toExponential(4));
document.write("<br>");
var num = 77.1234;
document.write(num.toExponential());
document.write("<br>");
var num = 77.1234;
var num = 77.1234;
document.write(num.toExponential(0));
</script>
</body>
</html>输出结果
7.7123e+1 7.71234e+1 8e+1