<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=UTF-8">
<script type="text/javascript">
//string
var str1=new String("abc");
var str2="abc";
alert(typeOf str1);
alert(typeOf str2);
var str3="javascript";
var reg1=/java/ig;
//i-ignorecase,不区分大小写匹配,g-globle全局匹配，m-多行匹配
alert(str3.match(reg1));
var res=str3.replace(reg1,"c++");
alert(res);
alert(str3.search(reg1));
var str4="138-031-403-447";
alert(str4.split.("-"));
//date
var date2=new Date("2021/9/22");
alert(date2.toLocaleString());
</script>
<title>
</title>
</head>
<body>
对象
</body>
</html>
typeOf的o没有大写应该是typeof，然后再把split的.去掉
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=UTF-8" />
<script type="text/javascript">
//string
var str1 = new String("abc");
var str2 = "abc";
alert(typeof str1);//这里改
alert(typeof str2);//这里改
var str3 = "javascript";
var reg1 = /java/gi;
//i-ignorecase,不区分大小写匹配,g-globle全局匹配，m-多行匹配
alert(str3.match(reg1));
var res = str3.replace(reg1, "c++");
alert(res);
alert(str3.search(reg1));
var str4 = "138-031-403-447";
alert(str4.split("-"));//这里改
//date
var date2 = new Date("2021/9/22");
alert(date2.toLocaleString());
</script>
<title> </title>
</head>
<body>
对象
</body>
</html>
split后面没.
str4.split.() 多了一点
看看浏览器里console的报错split.() .去掉或者你直接把代码发出来
alert(typeof(str1)); typeof(); 就是小写 o 方法加括号