<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<p>整数最多为 15 位。</p>

<button onclick="myFunction()">点我</button>

<p id="demo"></p>

<script>
function myFunction() {
    var x = 999999999999999;
    var y = 9999999999999999;
    document.getElementById("demo").innerHTML = x + "<br>" + y;
}
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<script>
var x;
document.write("<p>仅显示17位: ");
x=12345678901234567890;
document.write(x + "</p>");
document.write("<p>0.2 + 0.1 = ");
x=0.2+0.1;
document.write(x + "</p>");
document.write("<p>可以通过乘以10或除以10来计算: ");
x=(0.2*10+0.1*10)/10;
document.write(x +"</p>");
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<script>
var y = 0377;
var z = 0xFF; 
document.write(y + "<br>");
document.write(z + "<br>");
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<script>
var myNumber = 128;
document.write(myNumber + ' 十进制<br>');
document.write(myNumber.toString(16) + ' 十六进制<br>');
document.write(myNumber.toString(8) + ' 八进制<br>');
document.write(myNumber.toString(2) + ' 二进制<br>');
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<script>
myNumber=2;
while (myNumber!=Infinity){
    myNumber=myNumber*myNumber;
    document.write(myNumber +'<BR>');
}
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<script>
var x = 2/0;
var y = -2/0;
document.write(x + "<br>");
document.write(y + "<br>");
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
    
<p>一个数字除以一个字符串结果不是一个数字</p>
<p>一个数字除以一个字符串数字结果是一个数字</p>
<p id="demo"></p>
<script>
var x = 1000 / "Apple";
var y = 1000 / "1000";
document.getElementById("demo").innerHTML = isNaN(x) + "<br>" + isNaN(y);
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
    
<p id="demo"></p>
<script>
var y = 1000 / 0;
document.getElementById("demo").innerHTML = isNaN(y);
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<p id="demo"></p>

<script>
var x = 123;              // x 是一个数字
var y = new Number(123);  // y 是一个对象
var txt = typeof(x) + " " + typeof(y);
document.getElementById("demo").innerHTML=txt;
</script>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<p id="demo"></p>

<script>
var x = 123;              // x 是一个数字
var y = new Number(123);  // y 是一个对象
document.getElementById("demo").innerHTML = x===y;
</script>

</body>
</html>