【Java每日一题】20161207

20161206问题解析请点击今日问题下方的“【Java每日一题】20161207”查看

package Dec2016;

public class Ques1207 {

    public static void main(String[] args) {
        new Test();
        new Test(1);
        new Test("1");
        System.out.println("实例数量为："+Test.getNumOfInstances());
    }
}

class Test{
    private static int numOfInstances = 0;  // 记录多少个实例

    {
        numOfInstances++;  // 构造代码块，计算实例数量
    }

    public Test(){
    }

    public Test(int num){
    }

    public Test(String str){
        this();  // 调用无参构造函数
    }

    // 返回创建的实例数量
    public static int getNumOfInstances(){
        return numOfInstances;
    }
} 

今日问题：
请问主程序能否正常运行输出结果？（点击以下“【Java每日一题】20161207”查看20161206问题解析）

题目原发布于公众号、简书：[url=http://mp.weixin.qq.com/s?__biz=MzI4ODEyMTgwMA==&mid=2650163293&idx=1&sn=54a9af14fb74f1bc4e60e139dc665b97&chksm=f3c1defac4b657ecd3ea61f46c0eb1edb6f5685bf517c3ad3e0713301c6444b0efcf65d24132#rd]【Java每日一题】20161207[/url]，[url=http://www.jianshu.com/p/6e5b781fade3]【Java每日一题】20161207[/url]

[img]https://img-blog.youkuaiyun.com/20161017115128961?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast[/img]