zoukankan      html  css  js  c++  java
  • int和Integer比较详解

    先看代码

            @Test
        public void testEquals() {
            int int1 = 12;
            int int2 = 12;
            
            Integer integer1 = new Integer(12);
            Integer integer2 = new Integer(12);
            Integer integer3 = new Integer(127);
            
            Integer a1 = 127;
            Integer a2 = 127;
            
            Integer a = 128;
            Integer b = 128;
                
            System.out.println("int1 == int2 -> " + (int1 == int2));  //true                    
            System.out.println("int1 == integer1 -> " + (int1 == integer1));  //true            
            System.out.println("integer1 == integer2 -> " + (integer1 == integer2));     //false
            System.out.println("integer3 == a1 -> " + (integer3 == a1));    //false
            System.out.println("a1 == a2 -> " + (a1 == a2)); //true                            
            System.out.println("a == b -> " + (a == b));//false                                                    
        }   
    1. 首先int1=int2不需要解释了
    2. int1==integer1是因为Integer与int比较时会自动拆箱成int。这里的Integer不管是直接赋值还是new出来的对象。只要是和int比较都会自动拆箱。
    3. integer1和integer2两者都是对象,不会拆箱。所以不相等
  • 相关阅读:
    文件输出debug
    sweetalert
    js认清this的第一步
    Creating default object from empty value in PHP?
    matplotlib画图
    python解析库
    zabbix监控ssl证书过期时间
    aws 预留实例到期监控
    aws ec2挂载 s3
    aliyun挂载oss
  • 原文地址:https://www.cnblogs.com/dbutil/p/10102211.html
Copyright © 2011-2022 走看看