Problem Description

Write a Java program to check if a given string is numeric (contains a valid number).

Code

CheckNumeric.java

public class CheckNumeric {
    public static void main(String[] args) {
        String string = "12345.15";
        boolean numeric = true;

        try {
            Double num = Double.parseDouble(string);
        } catch (NumberFormatException e) {
            numeric = false;
        }

        if(numeric)
            System.out.println(string + " is a number");
        else
            System.out.println(string + " is not a number");
    }
}

Output

12345.15 is a number

Explanation

Double.parseDouble(): Attempts to convert the string to a double.
NumberFormatException: Thrown if the string is not a valid number.
Try-Catch: Used to handle the exception and determine validity.

Java Program to Check if String is Numeric

Problem Description

Code

Output

Explanation

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