Java - making user input into arrays

Question

So I am super new in terms of coding and java, I just started this week but am already stuck at a pretty simple problem. I am supposed to first check that there are only five integers that the user inputs (on the same line) - which I have tried to do and maybe succeeded?

But then, if the user does input five integers, I am supposed to make that input into an array with integers and I just have no idea how to do that. I tried to figure it out on my own but I simply didn't understand what to do. Could anyone explain this to me, I'd be very grateful!

Here is my (probably very lacking) code:

import java.util.Scanner;

public class Try2 {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String inputR = in.nextLine(); 
        int lengthArgs = 5;
        int nummer = (inputR.split(" ").length);    
        if(nummer == lengthArgs) {
         //???
        }
        else {
          System.out.println("Wrong");
        }
    }
}

Your question has already been answered :) please look at; stackoverflow.com/questions/8348591/… — Jasper Lankhorst
– Jasper Lankhorst, Commented Feb 23, 2020 at 17:52
1) I assume you're probably using an IDE like Eclipse or IntelliJ. Please familiarize yourself with its debugger. First task: confirm that inputR.split(" ") gives you 5 elements. 2) Change "nummer" to number (misspellings just look bad). 3) Use new int[]. 4) Use Integer.praseInt() — paulsm4
– paulsm4, Commented Feb 23, 2020 at 17:53

OldProgrammer · Accepted Answer · 2020-02-23 17:55:26Z

1

You are already splitting the input into an array, but not retaining it. Try this:

  Scanner in = new Scanner(System.in);
    String inputR = in.nextLine(); 
    int lengthArgs = 5;
    String[] values inputR.split(" ");

    if(values.length == lengthArgs) {
        int[] numbers = new int[values.length];
        for(int i = 0;i < lengthArgs;i++) {
          // Note that this is assuming valid input
          // If you want to check then add a try/catch 
          numbers[i] = Integer.parseInt(values [i]);
       }
   }else {
   System.out.println("Wrong");

answered Feb 23, 2020 at 17:55

OldProgrammer

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Comments

tjago · Accepted Answer · 2020-02-23 18:00:38Z

1

Another idea, not so simple as array, but more elegant is with using Collection of Integers, like this:

public static void main(String[] args) {

    Scanner in = new Scanner(System.in);
    String inputR = in.nextLine();
    String inputs[] = inputR.split(" ");

    if(inputs.length != 5) {
        System.out.println("Invalid number of input");
    }

    List<Integer> integers = new ArrayList<>();
    for (String s : inputs) {
        Integer number = Integer.parseInt(s);
        integers.add(number);
    }
    System.out.println("Got following numbers in my input: "  + integers);
}

answered Feb 23, 2020 at 18:00

tjago

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Comments

JavaMan · Accepted Answer · 2020-02-23 17:58:26Z

import java.util.Arrays;
import java.util.Scanner;

public class Test {
public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    int lengthArgs = 5;

    String[] enteredChars;
    do {
        System.out.println("enter " + lengthArgs + "  numbers");
        enteredChars = in.nextLine().split(" ");
    } while (enteredChars.length != lengthArgs);

    int[] array = new int[lengthArgs];
    for (int i = 0; i < lengthArgs; i++) {
        try {
            array[i] = Integer.parseInt(enteredChars[i]);
        } catch (NumberFormatException e) {
            e.printStackTrace();// You have to do make sure that than you again have to enter all x numbers
        }
    }

    System.out.println("Your array " + Arrays.toString(array));
}
}

Karan Malhotra · Accepted Answer · 2020-02-23 18:12:04Z

0

You can just do this.

 Scanner in  = new Scanner(System.in);
     int arr[] = new int [5];
      for(int i = 0; i < 5; i++){
       int a = in.nextInt();
       arr[i] = a;
       }

      for(int i : arr)
          System.out.print(i + " ");

edited Feb 23, 2020 at 18:12

answered Feb 23, 2020 at 17:56

Karan Malhotra

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