package com.jvm;

import org.junit.Test;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

//P316

public class K_K {

static Logger logger = LoggerFactory.getLogger(K_K.class);

@Test

public void test01(){

Integer min = new Integer(12);

Integer big = new Integer(52456);

System.out.println(min.equals(12));

System.out.println(big.equals(52456));

}

public static void main(String[] args) {

String a1 = null;

logger.info("{}", a1);

Integer a = 1;

Integer b = 2;

Integer c = 3;

Integer d = 3;

Integer e = 321;

int ei = 321;

Integer f = 321;

Long g = 3L;

System.out.println(c == d); //封装类 == 比较，比较地址。-128<= 封装类 < 127 的时候读取缓存中的封装类，地址相等

System.out.println(e == f); //封装类值大于127，都是重新new对象，地址不相等

System.out.println(ei == f); // + - * / == 都会自动拆箱，比较数值

System.out.println(c == (a + b));

System.out.println(c.equals(a + b)); //equals(Object obj) 形参是对象，a+b自动装箱，封装类比较

System.out.println(g == (a + b)); //类型不一样也是自动拆箱，比较数值

System.out.println(g.equals(a + b)); //封装类.equals()都是封装类比较

}

}