题目:取一个整数a从右端开始的4~7位。
package cn.ls.lanqiao;
import java.util.*;
public class Test32 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("请输入一个7位及7位以上的正整数:");
long n = sc.nextLong();
result(n);
}
public static void result(long n) {
Scanner sc = new Scanner(System.in);
String s = Long.toString(n);
if (s.length() < 7) {
System.out.print("输入错误,请重新输入:");
long x = sc.nextLong();
result(x);
} else {
String s1 = s.substring(s.length() - 7, s.length() - 3);
System.out.println(s1);
}
}
}