From ecf0e75e0344195a9a2b3b9d6ebfe6c49b996968 Mon Sep 17 00:00:00 2001
From: huyidi <1013792433@qq.com>
Date: Sun, 10 Feb 2019 20:15:05 +0800
Subject: [PATCH] Added a command to output total number of contacts in the
 addressbook

Simple feature but straightforward and useful to manage memory space
---
 src/seedu/addressbook/commands/Command.java   |  1 +
 .../addressbook/commands/TotalCommand.java    | 30 +++++++++++++++++++
 src/seedu/addressbook/parser/Parser.java      |  4 +++
 3 files changed, 35 insertions(+)
 create mode 100644 src/seedu/addressbook/commands/TotalCommand.java

diff --git a/src/seedu/addressbook/commands/Command.java b/src/seedu/addressbook/commands/Command.java
index 2ff8f1575..59418b10e 100644
--- a/src/seedu/addressbook/commands/Command.java
+++ b/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;
     }
diff --git a/src/seedu/addressbook/commands/TotalCommand.java b/src/seedu/addressbook/commands/TotalCommand.java
new file mode 100644
index 000000000..3e7a9399c
--- /dev/null
+++ b/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");
+    }
+}
+
+
diff --git a/src/seedu/addressbook/parser/Parser.java b/src/seedu/addressbook/parser/Parser.java
index abddb3f45..ba2f84ce1 100644
--- a/src/seedu/addressbook/parser/Parser.java
+++ b/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);