diff --git a/src/seedu/addressbook/AddressBook.java b/src/seedu/addressbook/AddressBook.java
index 5a158b67..5e19d552 100644
--- a/src/seedu/addressbook/AddressBook.java
+++ b/src/seedu/addressbook/AddressBook.java
@@ -22,6 +22,7 @@
 import java.util.Optional;
 import java.util.Scanner;
 import java.util.Set;
+import java.util.PrimitiveIterator.OfDouble;
 
 /*
  * NOTE : =============================================================
@@ -183,6 +184,8 @@ public class AddressBook {
      */
     private static final ArrayList<String[]> ALL_PERSONS = new ArrayList<>();
 
+
+
     /**
      * Stores the most recent list of persons shown to the user as a result of a user command.
      * This is a subset of the full list. Deleting persons in the pull list does not delete
@@ -194,6 +197,17 @@ public class AddressBook {
      * The path to the file used for storing person data.
      */
     private static String storageFilePath;
+    
+	/* 
+	 * NOTE : =============================================================================================
+	 *     Number of arguments while reading input.
+	 * ====================================================================================================
+	 */
+	private static final int SINGLE_ARGUMENT = 1;
+	private static final int NULL_ARGUMENT = 0;
+
+	private static final int ZERO = 0;
+	private static final int TWO = 2;
 
     /*
      * NOTE : =============================================================
@@ -257,16 +271,12 @@ private static void echoUserCommand(String userCommand) {
      * @param args full program arguments passed to application main method
      */
     private static void processProgramArgs(String[] args) {
-        if (args.length >= 2) {
+        if (args.length > SINGLE_ARGUMENT) {
             showToUser(MESSAGE_INVALID_PROGRAM_ARGS);
             exitProgram();
-        }
-
-        if (args.length == 1) {
+        } else if (args.length == SINGLE_ARGUMENT) {
             setupGivenFileForStorage(args[0]);
-        }
-
-        if(args.length == 0) {
+        } else if (args.length == NULL_ARGUMENT) {
             setupDefaultFileForStorage();
         }
     }
@@ -281,10 +291,10 @@ private static void setupGivenFileForStorage(String filePath) {
         if (!isValidFilePath(filePath)) {
             showToUser(String.format(MESSAGE_INVALID_FILE, filePath));
             exitProgram();
+        } else {
+        	storageFilePath = filePath;
+        	createFileIfMissing(storageFilePath);
         }
-
-        storageFilePath = filePath;
-        createFileIfMissing(filePath);
     }
 
     /**
@@ -321,7 +331,16 @@ private static boolean isValidFilePath(String filePath) {
         } catch (InvalidPathException ipe) {
             return false;
         }
-        return hasValidParentDirectory(filePathToValidate) && hasValidFileName(filePathToValidate);
+        
+        if (hasValidParentDirectory(filePathToValidate) == false) {
+        	return false;
+        }
+        
+        if (hasValidFileName(filePathToValidate) == false) {
+        	return false;
+        }
+        
+        return true;
     }
 
     /**
@@ -339,8 +358,20 @@ private static boolean hasValidParentDirectory(Path filePath) {
      * If a file already exists, it must be a regular file.
      */
     private static boolean hasValidFileName(Path filePath) {
-        return filePath.getFileName().toString().lastIndexOf('.') > 0
-                && (!Files.exists(filePath) || Files.isRegularFile(filePath));
+        
+    	if (filePath.getFileName().toString().lastIndexOf('.') > ZERO) {
+        	return true;
+        }
+        
+        if (Files.exists(filePath) == false) {
+        	return true;
+        }
+        
+        if (Files.isRegularFile(filePath) == true) {
+        	return true;
+        }
+        
+        return false;
     }
 
     /**
@@ -394,8 +425,8 @@ private static String executeCommand(String userInputString) {
      * @return  size 2 array; first element is the command type and second element is the arguments string
      */
     private static String[] splitCommandWordAndArgs(String rawUserInput) {
-        final String[] split =  rawUserInput.trim().split("\\s+", 2);
-        return split.length == 2 ? split : new String[] { split[0] , "" }; // else case: no parameters
+        final String[] split =  rawUserInput.trim().split("\\s+", TWO);
+        return split.length == TWO ? split : new String[] { split[0] , "" }; // else case: no parameters
     }
 
     /**
@@ -989,12 +1020,12 @@ private static String extractPhoneFromPersonString(String encoded) {
 
         // phone is last arg, target is from prefix to end of string
         if (indexOfPhonePrefix > indexOfEmailPrefix) {
-            return removePrefixSign(encoded.substring(indexOfPhonePrefix, encoded.length()).trim(),
+            return removePrefix(encoded.substring(indexOfPhonePrefix, encoded.length()).trim(),
                     PERSON_DATA_PREFIX_PHONE);
 
         // phone is middle arg, target is from own prefix to next prefix
         } else {
-            return removePrefixSign(
+            return removePrefix(
                     encoded.substring(indexOfPhonePrefix, indexOfEmailPrefix).trim(),
                     PERSON_DATA_PREFIX_PHONE);
         }
@@ -1012,12 +1043,12 @@ private static String extractEmailFromPersonString(String encoded) {
 
         // email is last arg, target is from prefix to end of string
         if (indexOfEmailPrefix > indexOfPhonePrefix) {
-            return removePrefixSign(encoded.substring(indexOfEmailPrefix, encoded.length()).trim(),
+            return removePrefix(encoded.substring(indexOfEmailPrefix, encoded.length()).trim(),
                     PERSON_DATA_PREFIX_EMAIL);
 
         // email is middle arg, target is from own prefix to next prefix
         } else {
-            return removePrefixSign(
+            return removePrefix(
                     encoded.substring(indexOfEmailPrefix, indexOfPhonePrefix).trim(),
                     PERSON_DATA_PREFIX_EMAIL);
         }
@@ -1144,14 +1175,14 @@ private static String getUsageInfoForExitCommand() {
      */
 
     /**
-     * Removes sign(p/, d/, etc) from parameter string
+     * Removes prefix(p/, d/, etc) from parameter string
      *
-     * @param s  Parameter as a string
-     * @param sign  Parameter sign to be removed
-     * @return  string without the sign
+     * @param fullString  Parameter as a string
+     * @param prefix  Parameter sign to be removed
+     * @return  string without the prefix
      */
-    private static String removePrefixSign(String s, String sign) {
-        return s.replace(sign, "");
+    private static String removePrefix(String fullString, String prefix) {
+        return fullString.replace(prefix, "");
     }
 
     /**