Question

Write a program which (1) reads a double number from a user, and (2) stores the Math.sqrt of the number if it is > 0 and -1 otherwise into a variable named answer, and (3) return answer.

Answer 1

import java.util.Scanner;

public class NumberSquareRoot {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a number: ");
        double number = in.nextDouble();
        double answer;
        if (number > 0) {
            answer = Math.sqrt(number);
        } else {
            answer = -1;
        }
        System.out.println(answer);
    }
}