public class Demo5_Integer {
public static void main(String[] args) {
Integer i1 = new Integer(97);
Integer i2 = new Integer(97);
System.out.println(i1 == i2);//new 是在堆内存中创建对象,i1与i2所指向的对象不同. false
System.out.println(i1.equals(i2)); //Integer重写了Object的equals()的方法 true
System.out.println("------------------------------");
Integer i3 = new Integer(197);
Integer i4 = new Integer(197);
System.out.println(i3 == i4); //false
System.out.println(i3.equals(i4)); //true
System.out.println("------------------------------");
Integer i5 = 127;
Integer i6 = 127;
System.out.println(i5 == i6); //true
System.out.println(i5.equals(i6)); //true
System.out.println("------------------------------");
/*-128到127是byte的取值范围,如果在这个取值范围内,自动装箱就不会新创建对象,而是从常量池中获取;
* 如果超过了byte取值范围就会再新创建对象.
* */
Integer i7 = 128;
Integer i8 = 128;
System.out.println(i7 == i8); //false
System.out.println(i7.equals(i8)); //true
System.out.println("------------------------------");
}
}
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