java下面程序如何实现用户输入非数字，能重新输入，直到正确输入跳出！
public class xixix {
public static void main(String[] args) {
System.out.println("*******************************");
System.out.println("请选择购买的商品编号："+"\n"+"1.T桖\t2.网球鞋\t3.网球拍");
System.out.println("*******************************");
String name="";
double price=0.0;
int num=0;
double sum=0;
String answer="y";
double total=0.0;
double playment=0.0;
double zheK=0.8;
int num1=0;
Scanner input =new Scanner(System.in);
while("y".equals(answer)){
System.out.println("请输入商品编号：");
while (!input.hasNextInt()){
System.out.println("请输入正确的商品编号!");
return ;
}
num=input.nextInt();
System.out.println("请输入购买数量：");
if(!input.hasNextInt()){
System.out.println("请输入正确数字!");
return;
}
num1=input.nextInt();
switch (num) {
case 1:
name="T桖";
price=245.0;
sum=price*num1;
break;
case 2:
name="网球鞋";
price=245.0;
sum=price*num1;
break;
case 3:
name="网球拍";
price=245.0;
sum=price*num1;
break;
}
System.out.println(name+"\t"+"￥:"+"数量："+num1+"\t"+price+"合计："+sum);
System.out.print("是否继续（y/n）");
answer=input.next();
total+=sum;
if("n".equals(answer)){
System.out.println("折扣是："+zheK);
System.out.println("应付金额："+total*0.8);
System.out.print("实付金额：");
playment=input.nextDouble();
System.out.print("找钱："+(playment-total*0.8));
}
}
}
}
最新回答
冷巷
2024-11-08 02:57:45
public static boolean isNumeric(String str){
for(int i=str.length();--i>=0;){
int chr=str.charAt(i);
if(chr<48 || chr>57)
return false;
}
return true;
}
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