寬度百分比 不用高度畫正方形
不知寬高水平垂直居中
封裝一個方法返回字符串長度(漢字為2位)
antd-layout-ui 寫個方法變成駝峰
[] === ![]
輸出結(jié)果?
function fn(a) {
console.log(a);
var a = 123;
console.log(a);
function a() { }
console.log(a);
console.log(b);
var b = function () { }
console.log(b);
}
fn(1);
- 輸出結(jié)果?
a = 100;
function deme(e) {
function a() { }
arguments[0] = 2;
console.log(e);
if (a) {
var b = 123;
var c = function () { }
}
var c;
a = 10;
var a;
console.log(b);
f = 123;
console.log(c);
console.log(a);
}
var a;
deme(1);
console.log(a);
console.log(f);
- 輸出結(jié)果?
function fonn(x) {
console.log(arguments);
return x
}
fonn(1, 2, 3, 4, 5);
- 輸出結(jié)果?
function fonn(x) {
console.log(arguments);
return x
} ()
- 輸出結(jié)果
! function fu() {
console.log("執(zhí)行");
}();
- 輸出結(jié)果?
function fonn(x) {
console.log(arguments);
return x
} (1, 2, 3, 4, 5)
- 輸出結(jié)果?
var p1 = new Person();
p1.say();
p1.say();
var p2 = new Person();
p2.say();
- 輸出結(jié)果?
var x = 1; y = z = 0;
function add(n) {
return n = n + 1;
}
y = add(x);
function add(n) {
return n = n + 3;
}
z = add(x);
console.log(x, y, z);
- 輸出結(jié)果
var str = 'abc';
str += 1;
var test = typeof str; //string
if (test.length == 6) {
test.sign = "xyz"
}
console.log(test.sign);
- 分別輸出什么?
function Person(name, height) {
this.name = name;
this.height = height;
this.say = function () {
console.log(this.name);
}
// 不返回
//return this
//return {}
//return 123
}
var per1 = new Person('小王', 175);
//分別打印什么
console.log(per1.name);
- 打印什么?
Teacher.prototype.name = "ABBB";
function Teacher() {
}
var tea1 = new Teacher();
Teacher.prototype = {
name: "CDDDD"
}
console.log(tea1.name);
- 打印什么?
Teacher.prototype.name = "ABBB";
function Teacher() {
}
Teacher.prototype = {
name: "CDDDD"
}
var tea1 = new Teacher();
console.log(tea1.name);
- 頁面顯示什么
var obj = { name: "sum" };
var obj1 = Object.create(obj);
var ong = Object.create(null)
document.write(obj1)
document.write(ong)
- 手寫找出 body里面的 p 元素,并打印對應(yīng)的索引
- 輸出結(jié)果
let fn = function () {
let num = 1; //自由變量
return {
a: function () {
console.log(num);
},
b: function () {
num++;
}
};
};
let closure = fn();
fn = null;
closure.a();
