<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.box p{
color: black;
}
div.text{
color: red;
10px;
box-sizing: border-box;
padding: 3px;
}
</style>
<script>
this.b='2';
function abc(){
let b=1;
++b;
setTimeout(()=>{
test('fun test');
},0);
setTimeout(
test('test fun'),1000
);
console.log(b);
function test(str){
console.log(this.b)
this.b++;
console.log(str);
console.log(this.b)
console.log(this.b++);
}
}
abc();
</script>
</head>
<body>
<div class="box">
<p class="text">Welcome to Hetl</p>
</div>
</body>
</html>
考察：
1.下面文字的颜色与其所在盒子的实际宽度:' red , 视图宽度
2.js运行输出？
2 test fun 3 3 2 4 fun test 5 5
请实现如下语法功能：（5）.plus（3）.minus（2）=6；
考察点：链式调用；
Number.prototype.plus = function (num) { // 注：箭头函数会将this指向window
return this + num
}
Number.prototype.minus = function (num){
return this - num
}
var a = (5).plus(3).minus(2);
console.log(a)