cin*_*l45 6 javascript ecmascript-6
我正在玩ES6类,我的最终目标是了解类与构造函数与工厂函数之间的区别。我目前的理解是,构造函数和类基本上使用相同的设计模式,而类只是构造函数的新语法。基于此假设,我试图创建一些示例,以显示类/构造函数与工厂函数之间的对比。
在下面的示例中,我旨在返回新对象和继承的一些方法。
我的第一个示例使用类语法非常简单。
示例#1:类
class Person {
constructor(name, age, location, occupation) {
this.name = name;
this.age = age;
this.location = location;
this.occupation = occupation;
}
printDescription() {
console.log(`My name is ${this.name} and I'm ${this.age} years old. I live in ${this.location} and I work as a ${this.occupation}.`);
}
}
const firstUser = new Person('Tom', 30, 'Sydney', 'Teacher');
firstUser.printDescription();
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在第二个示例中,我尝试使用不同的方法来复制第一个示例,但是我不确定这是工厂构造函数还是工厂函数。
实施例#2: ?
function PersonMaker (name, age, location, occupation) {
let person = {name, age, location, occupation};
person.printDetails = () => {
console.log(`My name is ${name} and I'm ${age} years old. I live in ${location} and I work as a ${occupation}.`);
};
return person;
}
const secondUser = PersonMaker('Johnny', 25, 'London', 'Driver');
secondUser.printDetails();
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我需要澄清第二个示例中使用的模式,如果它不是工厂函数,我如何将其转换为一个?
因为它返回一个对象,所以它是一个工厂函数 -它已经在那里解释过。
构造函数的行为与此不同,它不返回值:
function Person(name, age, location, occupation){
this.name = name
this.age = age
this.location = location
this.occupation = occupation
}
Person.prototype.printDetails = function(){
console.log(`My name is ${this.name} and I'm ${this.age} years old. I live in ${this.location} and I work as a ${this.occupation}.`);
};
const secondUser = new Person('Johnny', 25, 'London', 'Driver');
secondUser.printDetails();
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我通过将原型扩展为单独的构造函数来使用方法的定义,并且您仍然可以在构造函数内定义方法:
function Person(name, age, location, occupation){
this.name = name
this.age = age
this.location = location
this.occupation = occupation
this.printDetails = function(){
console.log(`My name is ${this.name} and I'm ${this.age} years old. I live in ${this.location} and I work as a ${this.occupation}.`);
};
}
const secondUser = new Person('Johnny', 25, 'London', 'Driver');
secondUser.printDetails();
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