Java练习题9

public class SIM {long number;    SIM(long number){        this.number=number;    }    long getNumber(){        return number;    }}public class Phone { SIM sim; void setSIM(SIM card){ sim=card; } long lookNumber(){     return sim.getNumber(); }}public class Test9 {public static void main(String[] args) {SIM sim1=new SIM(11111111111L);        Phone phone=new Phone();        phone.setSIM(sim1);        System.out.println("手机号码："+phone.lookNumber());        SIM sim2=new SIM(22222222222L);        phone.setSIM(sim2);        System.out.println("手机号码："+phone.lookNumber());}}