简单工厂模式

  • 定义一个创建对象的类，由这个类来封装实例化对象的行为

实现

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class Database { 
    getDetails(){
        console.log(this.name);
    }
}

class Sql extends Database{ 
    constructor(){
        super();
        this.name = "Sql";
    }
}

class Mysql extends Database{ 
    constructor(){
        super();
        this.name = "Mysql";
    }
}

class MongoDB extends Database{ 
    constructor(){
        super();
        this.name = "MongoDB";
    }
}

class ConnectDatabase{ 
    getType(type) {
        switch (type) {
            case "Sql":
                return new Sql();
            case "Mysql":
                return new Mysql();
            case "MongoDB":
                return new MongoDB();
            default:
                throw new Error("参数错误");
        }
    }
}

var ConnectFn = new ConnectDatabase();

var ConnectSql = ConnectFn.getType("Sql");
ConnectSql.getDetails(); 

var ConnectMysql = ConnectFn.getType("Mysql");
ConnectMysql.getDetails(); 

var ConnectMongoDB = ConnectFn.getType("MongoDB");
ConnectMongoDB.getDetails();

参考链接