关于 单例

关于单例

 function SingleObject(id,name) {
        this.id=id;
        this.name=name;

    }
    //给他方法
    SingleObject.getInstance = (function () {
        let instance;//存储实例结果  相对于方法是全局变量
        return function (id,name) {

            if (!instance instanceof SingleObject) {  //instance未存值  第一次调用

                instance = new SingleObject(id,name);

            }
            return instance;
        };
    })()
    let obj1 = SingleObject.getInstance(1001,'admin');  
    let obj2 = SingleObject.getInstance(1002,'admin');//还是第一个obj 1 的值
    console.log(obj1);
    console.log(obj1 == obj2);