Integer 127细节

public class Zhenze {
// 待匹配字符串
/*
* int 比较 int 字节比较值
* integer integer 比较 -128-127 是true
* new 和 new 比较 无论如何都是 false
* int 和 new Integer 比较只要 值相等就ok
* */
public static void main(String[] args) {
Integer a = 127;
Integer b= 127;
Integer c = 128;
Integer d = 128;
System.out.println(a==b); // true
System.out.println(c==d); // false

/*
* -128 - 127 在常量池引用
* 其他常量池申请
* */
}
}Integer a = 100;
Integer b = 200;
Integer c = 100;
Integer d = 200;
System.out.println(Objects.equals(a,c)); true
System.out.println(Objects.equals(b,d)); truepublic static void main(String[] args) {
int a = 120;
Integer b = 120;
Integer c = new Integer(120);
System.out.println(a == b); // true
System.out.println(a == c); // true
System.out.println(b == c); // false
}

/**
*
*/
@Test
public void test25() {
int a = 300;
Integer b = 300;
Integer c = new Integer(300);
System.out.println(a == b); // true
System.out.println(a == c); // true
System.out.println(b == c); // false
}

/**
*
*/
@Test
public void test39() {
Integer a = 300;
Integer b = 300;
Integer c = 100;
Integer d = 100;
System.out.println(a == b); //false
System.out.println(c == d); // true
}