前端原型和原型链
<!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>前端原型和原型链</title> </head> <body> <script> //构造函数 // 实例成员： 实例成员就是在构造函数内部，通过this添加的成员。实例成员只能通过实例化的对象来访问。 // 静态成员： 在构造函数本身上添加的成员，只能通过构造函数来访问 function Animai(name, age) { this.name = name this.age = age } Animai.length = '2m' let dog = new Animai('小狗', '4') console.log(dog, 'dog') //Animai {name: '小狗', age: '4'} 'dog' let cat = new Animai('小猫', '5') console.log(cat, 'cat') //Animai {name: '小猫', age: '5'} console.log(dog.length, 'length') console.log(Animai.length, 'length') //undefined 'length' // Animai 2 </script> </body> </html>
前端基本数据类型
<!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>前端基本数据类型</title> </head> <body> <script> function test(){ console.log(1) } console.log(test,"test") </script> </body> </html>
设计模式单体模式
<!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>单体模式</title> </head> <body> <script> // 单体模式 只能实例化一次 每次返回的实例是同一对象 var Singleton = function (name) { this.name = name; }; Singleton.prototype.getName = function () { return this.name; } // 获取实例对象 var getInstance = (function () { var instance = null; return function (name) { console.log(name,"name") //如果实例不存在 重新新加个实例 if (!instance) { instance = new Singleton(name); } return instance; } })(); // 测试单体模式的实例 var a = getInstance("aa"); var b = getInstance("bb"); console.log(a,"a") //aa console.log(b,"b") //aa </script> </body> </html>
