how to check if a character is a number in java

Question

I was doing my java programming practice. I wrote a code to check if a charcter is a number:

   public static void main(String[] args) {

        String string = "-1234.15";
        String numeric ;

        numeric = string.matches("-?\\d+(\\.\\d+)?");

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

But it gives me error. Whats wrong in my code?

Answer 1

For this, Java has a boolean data type, which can take the values as True or False, A boolean type is declared with the boolean keyword and can only take the values True or False. However, it is more common to return boolean values from boolean expressions, for conditional testing (see below):

 public static void main(String[] args) {

        String string = "-1234.15";
        boolean numeric = true ;

        numeric = string.matches("-?\\d+(\\.\\d+)?");

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

Happy coding.