CODEWITHSUNDEEP
java
jules
jules

Reputation: 21

How do I check if the reader's input is between 500 and 1000? I am not sure if I'm on the right track

I am supposed to ask the reader to input a number and then check if it's between 500 and 1000, so i can add up the digits. But i don't know how to check if the number is between the interval. 

import java.util.Scanner;
public class AddNumbers {
  public static void main(String[]args){
    Scanner input = new Scanner (System.in);
    //Prompt user to enter number
    System.out.println("Enter a number between 500 and 1000:");
      String number;
    number=input.nextLine();

    //Get digits from number
    char numberDigit1 = number.charAt(0);
    char numberDigit2 = number.charAt(1);
    char numberDigit3 = number.charAt(2);

    //initialize variable
    String constant=500;
    String constant2=1000;

while (number.CompareTo(constant)){
  System.out.println("The sum of the digits is: " + ((number.charAt(0) +      (number.charAt(1) + (number.charAt(2))))));
                                                                          }
while (number.CompareTo(constant)){
  if (number<=0)
  System.out.println("****ERROR: THE NUMBER MUST BE BETWEEN 500 AND     1000****");
}

while (number.CompareTo(constant2)){
  if (number>=0)
    System.out.println("****ERROR: THE NUMBER MUST BE BETWEEN 500 AND 1000****");
}


    input.close();
  }
}

Upvotes: 0

Views: 298

Answers (2)

Scary Wombat
Scary Wombat

Reputation: 44834

This will not compile

String constant=500;
String constant2=1000;

But why are you even using Strings?

int constant=500;
int constant2=1000;

number=input.nextLine();

int realInt = Integer.parseInt (number);

if (realInt >= constant && realInt <= constant2) {
    // you still have `number` so

   int result = 0;
   for (char ch : number.toCharArray ())
   {
       result += Integer.valueOf ("" + ch);
   }
   System.out.println (result);
}

Upvotes: 1

Darshan Mehta
Darshan Mehta

Reputation: 30819

Instead of reading input as a string and converting it into an int, we can directly validate integer input e.g:

    Scanner scanner = new Scanner (System.in);

    int input;
    if(!scanner.hasNextInt()){
        System.out.println("Input must be a number.");
    }else{
        input = scanner.nextInt();
        if(input < 500 || input > 1000){
              System.out.println("****ERROR: THE NUMBER MUST BE BETWEEN 500 AND     1000****");
        }
    }

Upvotes: 0

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