包装类
装箱和拆箱
手动装箱
int n1 = 10;
Integer integer = new Integer(n1);
Integer integer1 = Integer.valueOf(n1);手动拆箱
int i = integer.intValue();自动装箱
int n2 = 20;
Integer integer2 = n2;自动拆箱
int n3 = integer2;int n1 = 10;
Integer integer = new Integer(n1);
Integer integer1 = Integer.valueOf(n1);int i = integer.intValue();int n2 = 20;
Integer integer2 = n2;int n3 = integer2;