<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Title</title>
<meta charset="UTF-8">
</head>
<body>
<script>
// （1）.var a=1;
// var b=a++; //先赋值，再运算
// alert(b); 1
// alert(a); 2
// （2）.var a=1
// var b= ++a;//先运算，再赋值
// alert(b); 2
// alert(a); 2
// var x=1;
// alert(x++); //1
// alert(++x);//3
// alert(x--);//3
// alert(--x);//1
// alert(x);// 1 // + B = A;// (1) A = var. 3;
// one yuan subtraction
Alert // (B); //. 3
// Alert (typeof (B)); // Number
// (2) A = var '. 3';
// + B = A;
// Alert (B); / /. 3
// Alert (typeof (B)); // Number
// (. 3) var A = 3.2;
// + B = A;
// Alert (B); // 3.2
// Alert (typeof (B) ) // Number
// (. 4) = A 'A123'
// + B = A;
// Alert (B); NaN3 //
// Alert (typeof (B)); // Number
// (. 5) var = a '. 3';
// B = -a;
// Alert (B); // -. 3
// Alert (typeof (B)); // number
// (. 6) NaN3 belonging to a particular type of value of number , when faced with an invalid string into a number, there will be a NaN data
var a = 'ABCD';
B = -a;
Alert (B); // NaN
alert(typeof(b));//number
</script>
</body>
</html>
The arithmetic operators javascript 1
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Origin www.cnblogs.com/startl/p/12231691.html
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