12345678910111213141516171819202122232425262728293031323334353637383940414243444546 |
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <meta name="viewport" content="width=device-width, initial-scale=1.0">
- <title>Document</title>
- </head>
- <body>
- <script>
- // 算数运算 + - * / %(取余/取模)
- // console.log(1+1);//2
- // console.log(1+'100'); //number + string 拼接
- // console.log(1 + true); //2
- // console.log(1 + false); //1
- // console.log(1 + undefined); //NaN 非法数字
- // console.log(1 + null); //1
- var a = 20;
- console.log("我今年"+a+"岁");
-
- // console.log(1-1);//0
- // console.log(1-'100');//-99
- // console.log(1 - true); //0
- // console.log(1-undefined);//NaN
- // console.log(1-null);//1
- // console.log(1*2);//2
- // console.log(1*'2');//2
- // console.log(2*false);//0
- // console.log(2*null);//0
- // console.log(2*undefined);//NaN
- // console.log(10/2);//5
- // console.log(10/'2');//5
- // console.log(30/false);//Infinity
- // console.log(30/null);//Infinity
- // console.log(30/undefined);//NaN
- console.log(11%3);//2
- console.log(11%'3');//2
- console.log(11%false);//NaN
- console.log(11%null);//NaN
- console.log(11%undefined);//NaN
- </script>
- </body>
- </html>
|