Java Program to Check Whether a Number is Positive or Negative

In this program, you'll learn to check whether a given number is positive or negative. This is done by using a if else statement in Java.

Example: Check if a Number is Positive or Negative using if else

public class PositiveNegative {

    public static void main(String[] args) {

        double number = 12.3;

        // true if number is less than 0
        if (number < 0.0)
            System.out.println(number + " is a negative number.");

        // true if number is greater than 0
        else if ( number > 0.0)
            System.out.println(number + " is a positive number.");

        // if both test expression is evaluated to false
        else
            System.out.println(number + " is 0.");
    }
}

When you run the program, the output will be:

12.3 is a positive number.

If you change the value of number to a negative number (say -12.3), the output will be:

-12.3 is a negative number.

In the above program, it is quite clear how variable number is checked to be positive or negative, by comparing it to 0.

If you're not sure, here is the breakdown:

  • If a number is greater than zero, it is a positive number.
  • If a number is less than zero, it is a negative number.
  • If a number equals to zero, it is zero.