CODEWITHSUNDEEP
javaarraysscopeinitializationjava.util.scanner
doncable
doncable

Reputation: 11

Java find lowest number messes up when inputting negative numbers

I have to find the lowest number in an array. It works when I manually make an array, but when I use a scanner to get numbers from the user and they put in a negative number, it does not consider the negative sign and acts as if the number is a positive number. Is there something scan.nextInt does to negative numbers that causes this?

System.out.println("Enter an array size.");
size = scan.nextInt();

int[] numbers = new int[size];

System.out.println("Enter each integer in the array and press Enter after each one.");

for(int i = 0; i < size; i++)
{
    numbers[i] = scan.nextInt();
}

for(int j = 0; j < size; j++)
{
    smallest = numbers[0];
    if (numbers[j] < smallest)
    {
        smallest = numbers[j];
    }
}

System.out.println("Smallest Number is " + smallest);

This is the code for reference

Upvotes: 0

Views: 1627

Answers (2)

Levent Divilioglu
Levent Divilioglu

Reputation: 11622

You have to initialize your smallest out of the loop, preferably at the beginning. And if you are going to find the smallest, assign it a big value (if largest, assign a very small value);

int smallest = Integer.MAX_VALUE;

Integer.MAX_VALUE is the greatest possible value that you can assign to an integer in Java.

And always remember to release the resources. You have to close the scanner object when you're done with it.

scan.close();   // always release resources

Here is the demo code;

Demo Code

import java.util.Scanner;

public class FindLowest {

    public static void main(String[] args) {
        // initialization of variables
        int size;
        Scanner scan = new Scanner(System.in);
        int smallest = Integer.MAX_VALUE;

        System.out.println("Enter an array size.");
        size = scan.nextInt();

        int[] numbers = new int[size];

        System.out.println("Enter each integer in the array and press Enter after each one.");

        for (int i = 0; i < size; i++) {
            numbers[i] = scan.nextInt();
        }

        scan.close();   // always release resources

        for (int j = 0; j < size; j++) {
//      smallest = numbers[0];          // dont initialize here, initialize at beginning
            if (numbers[j] < smallest) {
                smallest = numbers[j];
            }
        }

        System.out.println("Smallest Number is " + smallest);
    }
}

Output Sample

Enter an array size.
5
Enter each integer in the array and press Enter after each one.
1
-2
3
-4
5
Smallest Number is -4

Upvotes: 0

Scary Wombat
Scary Wombat

Reputation: 44854

You reset the smallest variable every loop.

Try initializing it before the loop.

    smallest = numbers[0];
    for(int j = 0; j < size; j++)
    {
      if (numbers[j] < smallest)
      {
        smallest = numbers[j];
      }
    }

Upvotes: 3

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