Implement factorial

anthonyc1 · anthonyc1 · commit 3147226ca020 · 2017-03-16T10:39:23.000-04:00
diff --git a/Factorial.java b/Factorial.java
@@ -0,0 +1,35 @@
+import java.util.Scanner;
+
+public class Factorial{
+
+	public static void main(String[] args){
+		Scanner input = new Scanner(System.in);
+		//Prompt user to enter integer
+		System.out.print("Enter a non-negative integer: ");
+		
+		//Proceed with factorial calculation only if inputted number is not negative
+		if(input.hasNextInt()){
+			int number = input.nextInt();
+			if (number < 0){
+				System.out.print("Cannot execute. Please enter a non-negative integer: ");
+				number = input.nextInt();
+		} else {
+			//Output of factorial for any non-negative number
+			System.out.println("The factorial of "+number+" will yield: "+factorial(number));
+		}
+		}	
+	}
+
+	//Factorial method
+	public static long factorial(int n){
+
+		if (n==0){
+			return 1;
+		} else if (n==1){
+			return 1;
+		} else {
+			return n * factorial(n-1);
+		}
+
+	}
+}
