DESKTOP-7J91214_20200905-张军强

1.问题

单例

//饿汉模式单例
public class Sun{
    private static final Sun SUN = new Sun();
    private Sun(){  
        super();
    }
    public static Sun getInstance(){
        return SUN;
    }
}

//懒汉模式单例
public class Earth{
    private static Earth earth ;
    private Earth(){
        super();
    }
    public static Earth getInstance(){
        if(earth == null){
            earth = new Earth();
        }
        return earth;
    }
}

2.吐槽

考试还是容易紧张，总是犯很低级的错误，简单问题还是做错了，这次居然16的平方算错了。

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