package zy;
import java.util.Scanner;
public class two {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner scan=new Scanner(System.in);
double x,y;
System.out.print("x=:");
x=scan.nextDouble();
y=scan.nextDouble();
if(x>1000)
System.out.println("x的值不能超过1000,请重新输入!");
if(x>=100&&x<=1000)
System.out.println("y="+3*x+-11);
if(10<=x&&x<20)
System.out.println("y="+2*x+-1);
if (0<x&&x<10)
System.out.println("y="+x);
if(x<0)
System.out.println("x必须为正,请重新输入!");
你在接收用户输入的时候,提示只写了x的,提示用户输入y美哦与写,你在控制台应该输入两个数回车后才有输出.可以改成下面代码
```java
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner scan = new Scanner(System.in);
double x, y;
System.out.print("x=:");
x = scan.nextDouble();
System.out.println("y=:");
y = scan.nextDouble();
if (x > 1000)
System.out.println("x的值不能超过1000,请重新输入!");
if (x >= 100 && x <= 1000)
System.out.println("y=" + 3 * x + -11);
if (10 <= x && x < 20)
System.out.println("y=" + 2 * x + -1);
if (0 < x && x < 10)
System.out.println("y=" + x);
if (x < 0)
System.out.println("x必须为正,请重新输入!");
}
```