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 set get 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>
