输入字符串和子串开始位置和长度，截取字符串的子串并输出

从键盘上输入一个字符串和子串开始的位置和长度，截取该字符串的子串并输出

import java.util.Scanner;

public class HelloWorld{

     public static void main(String []args){
        Scanner scanner = new Scanner(System.in);

        System.out.println("Please enter a string: ");
        String inputString = scanner.nextLine();
        
        System.out.println("Please enter start position and length of a substring within above string: ");
        int start = scanner.nextInt();
        int length = scanner.nextInt();
        
        String substring = inputString.substring(start, length);
        
        System.out.println("The substring is: " + inputString);        
     }
}