有没有会的帮我看一下

img

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <p></p>
</body>
</html>
<script>
    let mP=document.getElementsByTagName("p")[0]
    mP.innerHTML="helloword"
</script>
//如果要写js文件新建一个.js文件然后把script中的代码复制过去，在html中用src引进去就可以


2.


<script>
    let a=10;
    let b=100;
    if(a>b){
        alert(a +" "+typeof a)
    }else if(a<b){
        alert(b +" "+typeof b)
    }else{
        alert("a=b")
    }
</script>