<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>类型，值，变量</title>
</head>
<body>
</body>
<script type="text/javascript">
"use strict";//开启严格模式
var x=NaN;
console.log(isFinite(x));
console.log(isNaN(x));
var y=.3-.2;
var b=.2-.1;
console.log(y==b);
b=0.3-0.2;
y=0.2-0.1;
console.log(b==y);
console.log("日期");
var then=new Date(2017,3,30);
var later=new Date(2017,3,30,7,59);
var now=Date();
var elapsed=now -then;
console.log(then);
console.log(later);
console.log(now);
console.log(elapsed);
console.log(later.getDay());
console.log(later.getHours());
console.log("meislove\u000Aloveyou")
var str="meislove1lsfjld3lsfsk";
str.charAt(0);
str.substring(1,3);
str.slice(-3);//获得最后三个字符串
str.split('1');
str.indexOf("l");//首次出现的位置
str.lastIndexOf("l");//最后出现的位置
str.indexOf("l",2);//在位置2之后出现的字符l的位置
str.toUpperCase();//全部转换成大写
str.replace("h","H");//全文字符替换
var s="test";
s.len=4;
console.log("lovemeyyouhous:"+s.len +"and"+ s.length);
</script>
</html>
转载请注明原文地址: https://ju.6miu.com/read-670288.html
