How can you make a decimal input valid?

Question

I have written this code, however, every time I input a decimal value, it doesn't work. How can I make this code work even if I input a decimal value? For example, if I input a value of 7.5, it should display that "the shipping cost is $9.45"

    import java.util.Scanner;

public class IfElse {
  public static void main(String[] args) {
    int marksObtained;

    Scanner input = new Scanner(System.in);

    System.out.println("Please enter a package weight in pounds:");

    marksObtained = input.nextInt();

    if (marksObtained>20)
        {
            System.out.println("The package is too heavy to be shipped");
        }
        else if (marksObtained>10)
        {
            System.out.println("The shipping cost is $12.50");
        }
            else if (marksObtained>3)
        {
            System.out.println("The shipping cost is $9.45");
        }
            else if (marksObtained>1)
        {
            System.out.println("The shipping cost is $4.95");
        }
            else if (marksObtained>0)
        {
            System.out.println("The shipping cost is $2.95");
        }
        else if (marksObtained<0)
        {
            System.out.println("The weight must be greater than zero");
        }
  }
}

if you want to read decimal use `nextDouble()` and also check else if conditions — Ryuzaki L, Feb 05 '19 at 01:34
Glad to see that you have it sorted. Please upvote and accept an answer below — Scary Wombat, Feb 05 '19 at 01:42

score 1 · Answer 1 · answered Feb 05 '19 at 01:37

1

You can use nextFloat or nextDouble

Scanner s = new Scanner (System.in);
float a = s.nextFloat ();
System.out.println(a);

Using nextInt will expect an int value to be entered and will throw a java.util.InputMismatchException if a int is not entered

answered Feb 05 '19 at 01:37

Scary Wombat

44,617
6
35
64

score 1 · Answer 2 · answered Feb 05 '19 at 01:37

Look at the code that you use to read input:

int marksObtained;`enter code here`
marksObtained = input.nextInt();

The key here is to understand that an int can only represent whole number values, not decimals. For decimals, you need to use a double or a float. For example:

double marksObtained = input.nextDouble();

I suggest you go back and review the basic data types which Java supports. You should also familiarize yourself with the documentation for the Scanner class as well as the rest of the documentation for the standard Java APIs.

score 1 · Answer 3 · answered Feb 05 '19 at 01:38

1

nextInt() only works for integers. Use nextDouble()

answered Feb 05 '19 at 01:38

robbieperry22

1,753
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score 1 · Answer 4 · answered Feb 05 '19 at 01:42

Use nextDouble method as below

public static void main(String[] args) {
    double marksObtained;

    System.out.println("Please enter a package weight in pounds:");
    Scanner input = new Scanner(System.in);
    marksObtained = input.nextDouble();
    input.close();

    if (marksObtained > 20) {
        System.out.println("The package is too heavy to be shipped");
    } else if (marksObtained > 10) {
        System.out.println("The shipping cost is $12.50");
    } else if (marksObtained > 3) {
        System.out.println("The shipping cost is $9.45");
    } else if (marksObtained > 1) {
        System.out.println("The shipping cost is $4.95");
    } else if (marksObtained > 0) {
        System.out.println("The shipping cost is $2.95");
    } else if (marksObtained < 0) {
        System.out.println("The weight must be greater than zero");
    }
}

And close the scanner, it is good practice doing it.

How can you make a decimal input valid?

4 Answers4