package com.hspedu.wrapper_; public class Course463 { public static void main(String[] args) { method(); } public static void method() { Integer i = new Integer(1); Integer j = new Integer(1); System.out.println(i == j); // false // 自动装箱Integer.valueOf, // 源码如果在缓存数组-128-127则直接返回,超出部分new创建对象 Integer m = 1; Integer n = 1; System.out.println(m == n); // true Integer x = 128; Integer y = 128; System.out.println(x == y); // false } }
package com.hspedu.wrapper_; public class Course464 { public static void main(String[] args) { // 练习 Integer i1 = new Integer(127); Integer i2 = new Integer(127); System.out.println(i1 == i2); // false Integer i3 = new Integer(128); Integer i4 = new Integer(128); System.out.println(i3 == i4); // false Integer i5 = 127; Integer i6 = 127; System.out.println(i5 == i6); // true Integer i7 = 128; Integer i8 = 128; System.out.println(i7 == i8); // false Integer i9 = 127; Integer i10 = new Integer(127); System.out.println(i9 == i10); // false // 只要有基本数据类型 == 比较的是数值是否相等 Integer i11 = 127; int i12 = 127; System.out.println(i11 == i12); // true Integer i13 = 128; int i14 = 128; System.out.println(i13 == i14); // true } }