0402作业
16lz
2021-04-10
闭包
<!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><script>// let a = 89;// let b = 86;// let c = 90;// function sum(b, a) {// //内部变量// return b + a + c;// }// console.log(sum(29, 344));function demo1() {let email = "80883341@qq.com";return function child() {return email;};}alert(demo1()());// function demo2() {// let a = "2121";// }// alert(demo2);</script></body></html>
遍历数组
<!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><script>let colors = ["red", "blue", "green"];for (i = 0; i < colors.length; i++) {console.log(colors[i]);}</script></body></html>
静态方法
<!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><script>// 无需实例化(new)直接使用类名.方法调用class Users {constructor(name, email) {this.name = name;this.email = email;}show() {return {names: this.name,emails: this.email,age: this.#age,};}static fetch() {return this.UserName;return this;return "static+++++function";}//私有成员#age = 50;// 静态变量static UserName = "灭绝诗美";// 访问器属性：伪装成属性的方法 有get setget age() {return this.#age;}}const Account = new Users();console.log(Account.show());console.log(Users.#age);console.log(Users.age);// console.log(Users.fetch());// console.log(Users.UserName);</script></body></html>
类与继承
<!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><script>// function User(name, pass) {// this.name = name;// this.pass = pass;// this.show = function () {// return { name: this.name, email: this.email };// };// }// const user = new User("kowal", "kowalpass");// console.log(user);function User(name, pass) {this.name = name;this.pass = pass;// this.show = function () {// return {// name: this.name,// email: this.email,// };// };}User.prototype.show = function () {return { name: this.name, pass: this.pass };};const user = new User("kowal", "mima");console.log(user);console.log(user.show());const user1 = new User("pter", "jmvnnnnn");console.log(user1);console.log(user1.show());</script></body></html>
原型
<!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><script>// function f1() { // return "eeee"; // } alert(f1());// 任何一个函数都是对象，都有一个共通属性【prototype】// 何为原型：原型=父盒，提供原始参数，子元素可以继承父元素的原型属性//函数作为基本函数使用时 prototype属性基本无用，但依然作为函数的初始化属性// 当一个函数作为构造函数使用时，必须使用“new”关键字进行区别// 通过构造函数创建对象的过程为 对象实例化// 对象实例化后的对象可以看作为一个类//建立函数function User() {name = "kowal";ID = 80887765;pass = '90872udhn"';}// 当成普通函数进行调用;const user = User();// console.log(user);console.dir(user);// *******??当成构造函数调用 此时需用new关键字********const xcv = new User();console.dir(xcv);</script></body></html>
对象
<!-- <!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><script>class User1 {constructor(name, email) {this.name = name;this.email = email;}show() {return {name_show: this.name,email_show: this.email,};}get age() {return this.age;}#age = 50;}const Account1 = new User1("天彭老师", "80883341@qq.com");const Account2 = new User1("kowal", "5677765@qq.com");// console.log(Account);// console.log(typeof Account);// console.log(typeof User1);// console.log(Account.show());console.log(Account2.age());// console.log(Account2.show());// console.log(Account1.show());</script></body></html>
函数作用域
<!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><script>// 函数作用域let site = "PHPCN"; //全局site变量function getSite() {let site = "JDSC"; //函数内site变量return site;// 函数作用域查询的过程中，就拿site变量为例，查询中先以自身作用域内做检查，如果用site变量则返回该值，如果检查不到该变量则继续向外查询// 如果最后查不到该site变量那么提示undefind 未定义 这个过程叫做作用域链let domain = "baidu.com"; //私有变量，domain变量为内部变量，仅限于作用域内访问外部不可调用}// alert(getSite());alert(getSite());</script></body></html>
while循环
<!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><script>// const colors = ["red", "grenn", "blue"];// let j = 0;// while (j < colors.length) {// j++;// console.log(colors[j]);// }// 对象遍历 For-IN// const OBJEC = {// name: "kowal",// phone: "13082899878",// shooe: "Nike",// ID: 988898,// };// for (let xh in OBJEC) {// console.log(OBJEC[xh]);// }for (let i = 0; i <= 100; ) {console.log(i);i++;}</script></body></html>
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