封装类对象的缓存对象

public class Main {
    public static void main(String[] args) {
        /*
        * byte -- Byte -- [-128, 127)
        * short -- Short -- [-128,127)
        * int  -- Integer -- [-128,127)
        * long -- Long -- [-128,127)
        *
        * float -- Float -- 无
        * double -- Double -- 无
        * char -- Character -- [0,127)
        *
        * boolean -- Boolean -- true,false
        *
        * */
        Integer a1 = 10;
        Integer a2 = 10;
        System.out.println(a1 == a2);// true
        System.out.println(a1.equals(a2));// true

        Integer a3 = 128;
        Integer a4 = 128;
        System.out.println(a3 == a4);// false
        System.out.println(a3.equals(a4));// true
    }
}