Integer自动装箱和拆箱
Integer a=3; => Integer a=Integer.valueOf(3);
/** *@description: 自动装箱和拆箱 *@auther: yangsj *@created: 2019/4/2 15:48 */ @Test public void Test7(){ //自动装箱: Integer num = 12; //自动拆箱: System.out.println(num + 12);//24
//基本数据类型的对象缓存: // -128~127 输出true // 超过该范围,输出false Integer num1 = 12; Integer num2 = 12; System.out.println(num1 == num2);//true Integer num3 = 129; Integer num4 = 129; System.out.println(num3 == num4);//false //手动装箱 Integer num5 = Integer.valueOf(12); Integer num6 = Integer.valueOf(12); System.out.println(num5 == num6);//true Integer num7 = Integer.valueOf(128); Integer num8 = Integer.valueOf(128); System.out.println(num7 == num8);//false Integer num9 = new Integer(12); Integer num10 = new Integer(12); System.out.println(num9 == num10);//false }