[W5][M11-1]Hu Yidi

src/seedu/addressbook/commands/Command.java

@@ -60,6 +60,7 @@ protected ReadOnlyPerson getTargetPerson() throws IndexOutOfBoundsException {
         return relevantPersons.get(getTargetIndex() - DISPLAYED_INDEX_OFFSET);
     }
 
+
     public int getTargetIndex() {
         return targetIndex;
     }

src/seedu/addressbook/commands/TotalCommand.java

@@ -0,0 +1,30 @@
+package seedu.addressbook.commands;
+
+import seedu.addressbook.data.person.ReadOnlyPerson;
+
+import java.util.List;
+
+
+/**
+ * Lists all persons in the address book to the user.
+ */
+public class TotalCommand extends Command {
+
+    public static final String COMMAND_WORD = "total";
+
+    public static final String MESSAGE_USAGE = COMMAND_WORD
+            + ": Total number of persons in the address book.\n"
+            + "Example: " + COMMAND_WORD;
+
+
+    @Override
+    public CommandResult execute() {
+        List<ReadOnlyPerson> totalList = addressBook.getAllPersons().immutableListView();
+        int TOTALNUMBER = totalList.size();
+
+        return new CommandResult(TOTALNUMBER+" "+
+                "IS THE TOTAL NUMBER OF EXISTING CONTACTS");
+    }
+}
+
+

src/seedu/addressbook/parser/Parser.java

@@ -20,6 +20,7 @@
 import seedu.addressbook.commands.HelpCommand;
 import seedu.addressbook.commands.IncorrectCommand;
 import seedu.addressbook.commands.ListCommand;
+import seedu.addressbook.commands.TotalCommand;
 import seedu.addressbook.commands.ViewAllCommand;
 import seedu.addressbook.commands.ViewCommand;
 import seedu.addressbook.data.exception.IllegalValueException;
@@ -88,6 +89,9 @@ public Command parseCommand(String userInput) {
         case ListCommand.COMMAND_WORD:
             return new ListCommand();
 
+        case TotalCommand.COMMAND_WORD:
+            return new TotalCommand();
+
         case ViewCommand.COMMAND_WORD:
             return prepareView(arguments);