Question

The Double.parseDouble() method requires a String argument, but it fails if the String cannot be converted to a floating-point number. Write an application in which you try accepting a double input from a user and catch a NumberFormatException if one is thrown. The catch block forces the number to 0 and displays Value entered cannot be converted to a floating-point number. Following the catch block, display the number.

Answer 1

Answer:

1. import java.util.Scanner;
3. public class Main {
4.    public static void main(String[] args) {
5.        Scanner input = new Scanner(System.in);
6.        String numStr = input.nextLine();
7.        double num;
8.        try{
9.            num = Double.parseDouble(numStr);
10.        }
11.        catch(NumberFormatException e){
12.            num = 0;
13.            System.out.println("Value entered cannot be converted to a floating point number.");
14.        }
15.    }
16. }

Explanation:

The solution code is written in Java.

Firstly, we create a Scanner object and prompt user to input a number (Line 5-6). Next, we create a try -catch block and place the parseDouble inside the try block. If the input is invalid (e.g. "abc"), a NumberFormatException error will be thrown and captured and set the num to 0 and display the error message (Line 11 - 13).