為什么我用有參的構(gòu)造方法時(shí)候,只能輸出語句,卻不能給全局變量賦初值?
如題!求高手解釋
public class Telphone {
float screen;
float cpu;
float mem;
public Telphone(){
System.out.println("無參的構(gòu)造方法執(zhí)行了!");
}
public Telphone(float newScreen,float newCpu,float newMem){
screen=newScreen;
cpu=newCpu;
mem=newMem;
System.out.println("有參的構(gòu)造方法執(zhí)行了!");
}
}
public class InitialTelphone {
? ? ?public static void main(String[] args) {
Telphone phone=new Telphone();
Telphone PH=new Telphone(5.0f,1.4f,2.5f);
}
}
2016-01-27
public class InitialTelephone {
?? ?public static void main(String[] args) {
?? ??? ?Telephone phone2=new Telephone(1.0f,2.0f,2.0f);
?? ??? ?System.out.println(phone2.screen);//輸出phone2的屏幕大小
?? ??? ?System.out.println(phone2.cpu);//輸出phone2的cpu
?? ??? ?System.out.println(phone2.mem);//輸出mem
?? ?}
}
您輸入的參數(shù)有誤,自動(dòng)賦值3.5
有參的構(gòu)造方法執(zhí)行了!
3.5
2.0
2.0
創(chuàng)建對(duì)象時(shí),對(duì)象的參數(shù)本來就是不可見的。因?yàn)槟銢]有要求輸出這些參數(shù),添加這些輸出就可以了。
2016-01-25