Complete MP4

Assignments/MP4_CalebFontenot/src/mp4_calebfontenot/MP4_CalebFontenot.java

@@ -13,7 +13,8 @@ import java.util.Scanner;
  */
 public class MP4_CalebFontenot {
 
-    static boolean debug = true;
+    static boolean debug = false;
+    // Yes, I know the debugger exists. This is just a bit easier imho
 
     /**
      * If the result from Step 4 is divisible by 10, the card number is valid; otherwise, it is invalid. For example, the number 4388576018402626 is invalid, but the number 4388576018410707 is valid
@@ -136,7 +137,23 @@ public class MP4_CalebFontenot {
             if (userInput.equalsIgnoreCase("c")) {
                 System.out.print("Please enter a credit card number: ");
                 userInput = input.next();
-                break;
+                try { //Test to see if user has given us a string that looks like a credit card number
+                    //Does it sucessfully convert to an integer?
+                    Long.parseLong(userInput);
+                    
+                } catch(Exception e) {
+                    System.out.println("Invalid input: String doesn't look like a credit card, it failed successfully convert into an integer.");
+                    //break;
+                }
+                if (userInput.length() != 16) {
+                    System.out.println("Invalid input: String doesn't look like a credit card, incorrect length.");
+                    if (debug) {
+                        System.out.println("length: " + userInput.length());
+                    }
+                } else {
+                    break;
+                }
+                
             }
         }
         
@@ -153,7 +170,8 @@ public class MP4_CalebFontenot {
         String userInput = menu();
         if (userInput == "0") { // Stop program execution if credit card not entered
             System.out.println("Credit card not entered!");
-            System.exit(0);
+            //System.exit(0);
+            return;
         } 
         
         boolean creditCardValidity = MP4_CalebFontenot.isValid(userInput);