Integer简介

Posted 2021-02-13 hongchengshise

//      当创建范围为[-128,127]时
        Integer a = 1;
        Integer b = 1;
        Integer c = new Integer(1);
        System.out.println("a == b :" + (a == b));
        System.out.println("a == c :" + (a == c));
        System.out.println();
//      当创建范围不为[-128,127]时
        Integer d = 128;
        Integer e = 128;
        Integer f = new Integer(128);
        System.out.println("d == e :" + (d == e));
        System.out.println("d == f :" + (d == f));
        System.out.println("d e f 互不相等(false为正确测试结果)：" + (d == e || d == f || e == f));
        System.out.println();
//      包装类均为值传递
        Integer g = 0;
        Integer h = new Integer(130);
        Test1(g);
        Test2(h);
        System.out.println("g = "+g);
        System.out.println("h = "+h);
    }
    static void Test1(Integer t) {
        t = 1;
        System.out.println("Test1内:  t = " + t);
    }
    static void Test2(Integer t) {
        t = 131;
        System.out.println("Test2内:  t = " + t);
    }
}

原文：https://blog.csdn.net/Cactus_Lrg/article/details/81489299 

测试结果如下：

a == b :true
a == c :false

d == e :false
d == f :false
d e f 互不相等(false为正确测试结果)：false

Test1内: t = 1
Test2内: t = 131
g = 0
h = 130