User Guide

Ha(ppy)Bit is a desktop application aimed to empower students to achieve their goals—whether personal, academical, or health—amidst the hectic and stressful university life, through cultivating good habits. The application operates on a Command Line Interface (CLI) while still comprising features typically found in a Graphical User Interface (GUI). Students who type fast will find that Ha(ppy)Bit performs habit tracking more efficiently than your conventional GUI applications.

You can find out more about Ha(ppy)Bit’s Developer Guide or its developers (😀 us!) at our Main Page.

1. Quick Start
- 1.1 Start-Up Interface
- 1.2 Main Interface
2. Using this Guide
- 2.1 Terminology
- 2.2 Icons
3. Using Ha(ppy)Bit
- 3.1 Instructions from Ha(ppy)Bit
- 3.2 Command Format
4. Features
5. About Loading and Saving Data
6. FAQ
7. Command Summary
8. Useful Links

1. Quick Start

Hype yourself up by dancing. Here begins your journey with Ha(ppy)Bit.
Ensure you have Java 11 installed in your computer. If you do not have it installed, download it here.
Download the latest happybit.jar here.
Copy the file to the folder you want to use as the home folder for your Ha(ppy)Bit.
Open your terminal of choice inside the folder containing happybit.jar file.
Run the file by typing the command java -jar happybit.jar.

Upon loading the app you should see the following screen, indicating that you have successfully run the app.

==============================================================================
 _  _   __   ____  ____  _  _  ____  __  ____
/ )( \ / _\ (  _ \(  _ \( \/ )(  _ \(  )(_  _)
) __ (/    \ ) __/ ) __/ )  /  ) _ ( )(   )(
\_)(_/\_/\_/(__)  (__)  (__/  (____/(__) (__)     tracking habits made fun...
==============================================================================

Howdy! Welcome to Ha(ppy)Bit!
Select from one of the following menu items:
    [1] About HappyBit
    [2] User Guide
    [3] Developer Guide
    [4] Demo Video
    [5] Start Application
    [6] Exit Application
    
Option:

Any keyboard input will appear after Option: . Here is where interaction between you and Ha(ppy)Bit takes place.

1.1 Start-Up Interface

In the current loading screen, you will be able to navigate to five other screens. Choose an option from one to six by typing 1, 2, 3, 4, 5 or 6 and hitting “enter” to load the desired screen. Below are the outcomes.

Option 1: `About Ha(ppy)Bit`

Learn more about our vision for Ha(ppy)Bit and the team behind it.

Option: 1

Ha(ppy)Bit is a desktop application aimed to empower students to achieve their goals—whether personal,
academical, or health—amidst the hectic and stressful university life, through cultivating good
habits. The application operates on a Command Line Interface (CLI) while still comprising features
typically found in a Graphical User Interface (GUI). Students who type fast will find that Ha(ppy)Bit
performs habit tracking more efficiently than your conventional GUI applications.

Meet The Team
=================================================================
||  Tan Kah Heng       ||  Creative Director, Visionary        ||
||  Swaminathan Varun  ||  Business Manager, Technical Advisor ||
||  Tan Jun Heng Daren ||  Frontend Developer                  ||
||  Tan Hui En         ||  Backend Developer                   ||
||  Swann Tet Aung     ||  Backend Developer                   ||
=================================================================

Current Version: v2.1 (updated 08-Nov-2021)


Press enter to return to main menu...

Option 2: `User Guide`

Learn what you can accomplish with this app.
This option opens the User Guide in your web browser.

Option: 2

Opening in a web browser...

Press enter to return to main menu...

User Guide

Option 3: `Developer Guide`

Learn about the app from the perspective of a software engineer.
This option opens the Developer Guide in your web browser.

Option: 3

Opening in a web browser...

Press enter to return to main menu...

Developer Guide

Option 4: `Demo Video`

Don’t like reading long wordy guides? A video may be just the thing for you!
This option opens a Google Drive folder containing the Demo Video in your web browser.

Option: 4

Opening in a web browser...

Press enter to return to main menu...

Option 5: `Start Application`

If you’re a new user, look forward to beginning your Ha(ppy)Bit journey here.
If you’re a returning user, fret not! Everything you gained from your journey has been saved and will be loaded.
This option starts up the main interface of the application.

Option: 5

Starting application...
Type 'return' to return to main menu

Option 6: `Exit Application`

Why would you exit Ha(ppy)Bit even before trying out the main functionalities?
If you insist… this option exits the application.

Option: 6

________________________________________________________________________________________________________________________
Thanks for using Ha(ppy)Bit, see you in a bit! (hehe)

"We are what we repeatedly do. Excellence, then, is not an act, but a habit."
Will Durant
________________________________________________________________________________________________________________________

1.2 Main Interface

Upon formally starting the application, you should see the following screen. (See Start Application if you are unsure how to get here)

==============================================================================
 _  _   __   ____  ____  _  _  ____  __  ____
/ )( \ / _\ (  _ \(  _ \( \/ )(  _ \(  )(_  _)
) __ (/    \ ) __/ ) __/ )  /  ) _ ( )(   )(
\_)(_/\_/\_/(__)  (__)  (__/  (____/(__) (__)     tracking habits made fun...
==============================================================================

Command:

Any keyboard input will appear after Command: . Here is where interaction between you and Ha(ppy)Bit takes place.

2. Using this Guide

We understand there may be a lot to take in from this user guide. Here are some things to take note which may make the guide more friendly and helpful.

2.1 Terminology

Name	Description	Example
Goal	A long term achievement you wish to accomplish.	`Lose 5kg by Dec`
Habit	Checkpoints; small, actionable tasks to be done to achieve goal.	`Run 5km`
Interval	The frequency (in days) which you want the habit to recur.	`Run 5km every 7 days`

A timeline of what a goal with three different habits could be. | Made with Canva

Goals and habits
Here we distinguish between goals and habits. Although they are commonly used words, the way we design Ha(ppy)Bit is tightly integral to the way we define them above. We would also like you to know that the purpose of habits is to break down daunting, colossal goals into easy, bite-sized habits; tasks that you can complete within a day or as defined by your interval.

Intervals
An interval is the window period given for each repetition of a habit. This implementation saves you the hassle of recording similar habits that occurs periodically. Here are three things to note:

An interval length is not allowed to extend longer than your goal time frame. To explain with an example, a goal that starts and ends within a week is not allowed to have a habit with an interval longer than 7 days.
One-off habits (hey, an oxymoron!) are habits that do not repeat. This is achieved by setting the interval as 0, rather than any positive integer.
Recurring habits are habits that have an interval length of 1 or more day, but fulfill condition 1.

2.2 Icons

Unfamiliar symbols may confuse. Here is a comprehensive collection of all emojis and syntax we employ.

📃 Notes: important information you should take note of (especially if you encounter input errors)

⚠ Warning: avoid doing the things mentioned here at all costs (unless you’re feeling lucky)

💡 Pro-Tip! additional information that may make your tracking journey easier

😀 → Used to show the developers’ exuberance!!!

👍 → Used to show the developers’ love and support for you.

3. Using Ha(ppy)Bit

Ha(ppy)Bit comes with some quirks that might need some time getting used to. To get you up to speed and warmed up with Ha(ppy)Bit, here are instructions and command formats to follow. 👍

3.1 Instructions from Ha(ppy)Bit

You may have noticed the instructions Press enter to return to main menu..., Type 'return' to return to main menu, or Press enter ONCE to return to command mode... at the bottom of some responses from Ha(ppy)Bit. This is because Ha(ppy)Bit clears and refreshes the page after every command. Previously typed commands will also be cleared, so press the “up” key on your keyboard to navigate through recently typed commands.

Do follow the instructions before typing anything, lest Ha(ppy)Bit does not register your input. On the topic of inputs…

3.2 Command Format

Ha(ppy)Bit is very particular about your commands. You begin off with a “command” word to tell Ha(ppy)Bit the exact action to carry out (See Command Summary for all actions). The actions are then followed up with “parameters”, which are information you wish to pass to Ha(ppy)Bit to carry out the actions with it. The various parameters are prefixed with different flags, which help Ha(ppy)Bit identify and distinguish the type of parameters.

A command could look like this: add n/Run 2.4km g/1 i/7. Where,
add is the command word,
Run 2.4km, 1, and 7 are parameters,
and n/, g/, and i/ are flags.

📃 Don’t worry if you typed the command wrongly! Helpful error messages will pop up to advise you on what to change. 👍

Here are guidelines and tips for the command format:

Commands are only accepted when you see Command: on the screen (See Main Interface). If your inputs appear after Command: , you’re doing it right.
Commands may require one or more flags. You may choose to use the flags in any order but ensure that all flags for that command are present.
(e.g. add requires the n/, g/ and i/ flag, and possible variations include add n/habit 1 g/1 i/1 and add i/1 n/habit 1 g/1)
Commands with repeated parameters with the same flag will be accepted without error, however only the parameter that came first will be taken as valid. (e.g. update g/1 n/gibberish n/malarkey will be accepted as if it was update g/1 n/gibberish)
Parameters <goal_index> and <habit_index>can be checked with the commands list and view respectively.
Parameters enclosed in angle brackets <> are meant to be replaced.
(e.g. view g/<goal_index> could be view g/1)
Parameters enclosed within curly brackets, {} are optional
Parameters enclosed within square brackets, [] indicate that at least one of the parameters is required
Flags should have a whitespace before them
(e.g. view g/1 instead of viewg/1)

4. Features

Below are the commands supported by the application. Each section describes the function of each command and its format.

4.1 Ask for Help: `help`

What did you say? You’re not sure what the commands are? Relax, a help command exists.
This command displays a list of all possible commands. If an invalid command is typed, this command will be invoked by default.

Format: help

Output:

Here is the list of commands:
--------------------------------------------------------------------------------------------------------------
| Action                            | Format                                                                 | 
--------------------------------------------------------------------------------------------------------------
| open command list                 | help                                                                   | 
--------------------------------------------------------------------------------------------------------------
| set a goal                        | set n/<goal_name> { t/<goal_type> s/<start_date> } e/<end_date>        | 
--------------------------------------------------------------------------------------------------------------
| add a habit                       | add g/<goal_index> n/<habit_name> i/<interval>                         | 
--------------------------------------------------------------------------------------------------------------
| update a goal name/type/end date  | update g/<goal_index> [ n/<goal_name> t/<goal_type> e/<end_date> ]     | 
--------------------------------------------------------------------------------------------------------------
| change a habit name/interval      | change g/<goal_index> h/<habit_index> [ n/<habit_name> i/<interval> ]  | 
--------------------------------------------------------------------------------------------------------------
| list all goals                    | list                                                                   | 
--------------------------------------------------------------------------------------------------------------
| view all habits of a goal         | view g/<goal_index>                                                    | 
--------------------------------------------------------------------------------------------------------------
| remove a goal                     | remove g/<goal_index>                                                  | 
--------------------------------------------------------------------------------------------------------------
| delete a habit                    | delete g/<goal_index> h/<habit_index>                                  | 
--------------------------------------------------------------------------------------------------------------
| mark a habit as done              | done g/<goal_index> h/<habit_index>                                    | 
--------------------------------------------------------------------------------------------------------------
| return to start screen            | return                                                                 | 
--------------------------------------------------------------------------------------------------------------
| exit the application              | exit                                                                   | 
--------------------------------------------------------------------------------------------------------------
* Replace <> with relevant terms (Exp: <goal_name> --> goal 1)
* Items enclosed within { } are optional
* Items enclosed within [ ] need to have at least one of the parameters specified inside.
* Use 'list' and 'view' to check the goal and habit indexes respectively

Press enter ONCE to return to command mode...

4.2 Set a Goal: `set`

Sets a new goal for a long term achievement you wish to accomplish. Goals must have an end date while the goal type and start dates are optional (well, we wouldn’t want you to be procrastinating on your goals right?)

Format: set n/<goal_name> { t/<goal_type> s/<start_date> } e/<end_date>

Goal name can be any name of your choosing (however do keep within a 50-character limit).
Dates must be in DDMMYYYY format. For example, 01 January 2021 must be written as 01012020.
Goal type is an optional parameter and can take one of the following arguments
- sl → Sleep
- fd → Food
- ex → Exercise
- sd → Study
- df → Default (This will be the goal type if the parameter is omitted)
Start date is an optional parameter. Omitting it will set the start date as today.

Example:

Command 1: set n/Reduce spending s/29112021 e/29112022
Command 2: set n/Exercise more t/ex e/01012022
Command 3: set t/fd e/31122022 n/Become a vegetarian

Output 1: The goal '[DF] Reduce spending' has been added.
Output 2: The goal '[EX] Exercise more' has been added.
Output 3: The goal '[FD] Become a vegetarian' has been added.

⚠ If more than 8 numbers are used for the date, it will be rejected as an invalid command.

4.3 List all Goals: `list`

Can’t remember what goals you have? Use this command to list all the goals that you have set. In addition, you get to view some useful statistics.

Format: list

Example:

Command: list

Output:

3 goal(s) currently being tracked:
----------------------------------------------------------------------------------------------------------------
| Index   | Name                 | Type      | Start Date   | End Date     | Habit Count   | Completion Rate   |
----------------------------------------------------------------------------------------------------------------
| 1       | Reduce spending      | Default   | 29-Nov-2021  | 29-Nov-2022  | 0             | Not Applicable    |
----------------------------------------------------------------------------------------------------------------
| 2       | Exercise more        | Exercise  | 12-Nov-2021  | 01-Jan-2022  | 0             | Not Applicable    |
----------------------------------------------------------------------------------------------------------------
| 3       | Become a vegetarian  | Food      | 12-Nov-2021  | 31-Dec-2022  | 0             | Not Applicable    |
----------------------------------------------------------------------------------------------------------------

📃 Goal index may change if a goal is deleted. e.g. deleting the goal Exercise more will cause the index of Become a vegetarian to change from 3 to 2.

4.4 Update a Goal: `update`

Updates a parameter of a goal specified by its index.
(To err is human. That’s why we have the update feature; designed to be more forgiving, when we have the occasional oopsies. 👍 )

Format: update g/<goal_index> [ n/<goal_name> t/<goal_type> e/<end_date> ]

There must be at least one parameter changed - otherwise why call this command at all?
Goal Index has to be provided
Attributes being changed to must be different from original value - what would be the point otherwise?

Example:
Command 1: update g/1 n/Read more
Command 2: update g/2 e/31122021
Command 3: update g/1 t/sd e/31012022

Output 1: The goal name 'Reduce spending' has been updated to 'Read more'.
Output 2: The goal end date of goal 'Exercise more' has been changed from '01-Jan-2022' to '31-Dec-2021'.
Output 3: The goal type 'Default' has been updated to 'Study'.
The goal end date of goal 'Read more' has been changed from '29-Nov-2022' to '31-Jan-2022'.

💡 Inputting multiple flags will allow you to update multiple attributes at the same time. Extra invalid flags will be ignored.

4.5 Remove a Goal: `remove`

Removes a goal specified by its index.
(Life gets us sometimes. Things don’t go as planned. But this isn’t calling it quits. It’s admitting defeat today, but to return stronger to fight another time. We got ya fam.)

Format: remove g/<goal_index>

Example:

Command: remove g/1

Output:

________________________________________________________________________________________________________________________
The goal '[SD] Read more' has been removed.
________________________________________________________________________________________________________________________

📃 Goal index may change if a goal is deleted. Use the list command to check what the new goal indexes are.

4.6 Add a Habit: `add`

Adds a habit that is linked to a goal.
(Habits are meant to be easy and doable. Completing them over time, with consistent dedication, one of these habits will be the metaphorical straw that breaks the camel’s back. Your goals reached, without even pulling a muscle.)

Format: add n/<habit_name> g/<goal_index> i/<interval>

name your habit with an achievable and actionable task (e.g. Run 2.4 km, Sleep at 10 PM)
‘Interval’ is a number that indicates the period of time you have to complete the habit before the next cycle
‘Interval’ defined as 0 indicates a one-off habit; you only have to complete the habit once

Example:
Command 1: add n/Run 2.4km g/1 i/7
Command 2: add g/1 i/1 n/Do 20 pushups
Command 3: add i/14 n/Learn a vegetarian dish g/2

Output 1: The habit 'Run 2.4km' has been added to goal '[EX] Exercise more'
Output 2: The habit 'Do 20 pushups' has been added to goal '[EX] Exercise more'
Output 3: The habit 'Learn a vegetarian dish' has been added to goal '[FD] Become a vegetarian'

📃 You should notice a list of habits to be done on the main interface whenever a new habit is added.

4.7 Change a Habit: `change`

Change and update the name and/or interval of a habit.

Format: change g/<goal_index> h/<habit_index> [ n/<habit_name> i/<interval> ]

There must be at least one parameter changed - otherwise why call this command at all?
Goal Index and Habit Index has to be provided
Interval cannot be changed to 0
Interval added cannot exceed end date of goal from current date of change
Attributes being changed to must be different from original value - what would be the point otherwise?

Example:
Command 1: change g/2 h/1 i/7
Command 2: change n/Do 30 pushups h/2 g/1
Command 3: change g/1 h/1 n/Run 1.6km i/3

Output 1: The habit 'Learn a vegetarian dish' of goal 'Become a vegetarian' has its interval changed to '7'
Output 2: The habit 'Do 20 pushups' of goal 'Exercise more' has been changed to 'Do 30 pushups'
Output 3: The habit 'Run 2.4km' of goal 'Exercise more' has been changed to 'Run 1.6km'
The habit 'Run 1.6km' of goal 'Exercise more' has its interval changed to '3'

💡 Inputting multiple flags will allow you to update multiple attributes at the same time. Extra invalid flags will be ignored.

4.8 Complete a Habit: `done`

Mark a habit under a goal as done.
(Congratulations on the completed habit… for that cycle :P)

Format: done g/<goal_index> h/<habit_index>

Example:

Command: done g/1 h/1

Output:

________________________________________________________________________________________________________________________
The habit 'Run 1.6km' of goal '[EX] Exercise more' has been completed for 12112021 to 15112021.
The next interval will begin on 16112021
________________________________________________________________________________________________________________________

4.9 Delete a Habit: `delete`

Deletes a habit under a goal.
(This should be used as a last resort. Don’t give up, hang in there and make your habits stick.)

Format: delete g/<goal_index> h/<habit_index>

Example:

Command: delete g/1 h/2

Output:

________________________________________________________________________________________________________________________
The habit 'Do 30 pushups' of goal '[EX] Exercise more' has been deleted.
________________________________________________________________________________________________________________________

4.10 View all Habits: `view`

List all habits under a specific goal for a bird’s eye view on your goal.

Format: view g/<goal_index>

Example:

Command: view g/1

Output:

1 habit(s) currently being tracked for Exercise more:
-------------------------------------------------------------------------------------------------------
| Index   | Name       | Interval   | Completion   | Completed   | Remaining   | Expired   | Streak   |
-------------------------------------------------------------------------------------------------------
| 1       | Run 1.6km  | 3          | 5.56%        | 1           | 17          | 0         | 1        |
-------------------------------------------------------------------------------------------------------

4.11 Return to Start-Up: `return`

Return to the start-up interface.
(Where did that bring you? Back to the start.)

Format: return

Example:

Command: return

Output:

==============================================================================
 _  _   __   ____  ____  _  _  ____  __  ____
/ )( \ / _\ (  _ \(  _ \( \/ )(  _ \(  )(_  _)
) __ (/    \ ) __/ ) __/ )  /  ) _ ( )(   )(
\_)(_/\_/\_/(__)  (__)  (__/  (____/(__) (__)     tracking habits made fun...
==============================================================================

Howdy! Welcome to Ha(ppy)Bit!
Select from one of the following menu items:
    [1] About HappyBit
    [2] User Guide
    [3] Developer Guide
    [4] Demo Video
    [5] Start Application
    [6] Exit Application

Option:

4.12 Exit the Program: `exit`

Exit the program.
(Don’t stay on Ha(ppy)Bit too long. You have a life out there, go live it!)

⚠ Make sure to use this command before exiting the program to ensure that your data is saved properly.

Format: exit

Example:

Command: exit

Output:

________________________________________________________________________________________________________________________
Thanks for using Ha(ppy)Bit, see you in a bit! (hehe)
"We are what we repeatedly do. Excellence, then, is not an act, but a habit."
 — Will Durant
________________________________________________________________________________________________________________________

5. About Loading and Saving Data

Loading saved data:

Whenever you run the program, the program will automatically look for any saved data in the relative storage path, data/habits.txt.

If the storage file is found, data in the storage file will be loaded into the program.
If the storage file is not found, the program will create one for you at the relative storage path, data/habits.txt.

📃 The storage file will be set to read-only. This is such that users do not accidentally edit the data stored in the storage file and corrupt it.

Saving data:

Every time you make changes to any of your data, the changes are immediately reflected in the storage file. This is to ensure that in the event you closed the program without using the command exit, we can ensure that most of your data are saved.
Before you exit the program, the goals you set and the habits you have added are automatically saved in a text file at the relative storage path, data/habits.txt.

6. FAQ

Q: How do I transfer my data to another computer?
A: You can just copy-paste the habits.txt in the path data/habits.txt file from one computer to another and all your data will be there!

💡 Pro Tip! Have your home folder reside in a cloud storage service (OneDrive, iCloud, etc.) to sync your data between devices.

Q: Why are our commands synonyms of each other - remove and delete, set and add, etc.?
A: Well… we need a way to distinguish between goal and habit commands, and we want to avoid using command words such as gdelete and hdelete for goal and habit deletion respectively.

Q: Why do I have to hit “enter” every time I want to key in a new command?
A: We want you to confirm that you have called the correct command, or understand the error message after it pops up before the screen is cleared.

Q: Are there any books you recommend?
A: Data Structures and Algorithms in Java → here

7. Command Summary

Action	Command Format	Example
Get help	`help`	`help`
Set goal	`set n/<goal_name> { t/<goal_type> s/<start_date> } e/<end_date>`	`set n/Reduce spending e/31122022`
List goals	`list`	`list`
Update goal	`update g/<goal_index> [ n/<goal_name> t/<goal_type> e/<end_date> ]`	`update g/1 n/Decrease Spending`
Remove goal	`remove g/<goal_index>`	`remove g/1`
Add habit	`add g/<goal_index> n/<habit_name> i/<interval>`	`add n/Don't drink BBT g/1 i/3`
Change habit	`change g/<goal_index> h/<habit_index> [ n/<habit_name> i/<interval> ]`	`change g/1 h/2 i/3`
Done habit	`done g/<goal_index> h/<habit_index>`	`done g/1 h/1`
Delete habit	`delete g/<goal_index> h/<habit_index>`	`delete g/1 h/1`
View habits	`view g/<goal_index>`	`view g/1`
Return to Start-Up	`return`	`return`
Exit Program	`exit`	`exit`

8. Useful Links

Visit our Main Page to find more useful links.

Interested in what makes Ha(ppy)Bit tick? Visit our GitHub website to explore and geek out on. What did you say? An explanation for the inner workings? Okay, okay. Here is our Developer Guide.

What now? You prefer a guided walkthrough because of the digital age and the attention economy today where corporations bombard your with enticing information to profit off your valuable attention has shortened your attention span tremendously such that you don’t have the patience nor focus to sit down and refer to our User Guide which we have painstakingly written to be comprehensive for users like you in order to provide a better user experience to a new app they may be unfamiliar with? Fine! We get it! We have prepared a Demo Video for you, the guided walkthrough you oh so desired.

Watch our wacky Demo Video bloopers here!

User Guide

1. Quick Start

1.1 Start-Up Interface

Option 1: About Ha(ppy)Bit

Option 2: User Guide

Option 3: Developer Guide

Option 4: Demo Video

Option 5: Start Application

Option 6: Exit Application

1.2 Main Interface

2. Using this Guide

2.1 Terminology

2.2 Icons

3. Using Ha(ppy)Bit

3.1 Instructions from Ha(ppy)Bit

3.2 Command Format

4. Features

4.1 Ask for Help: help

4.2 Set a Goal: set

4.3 List all Goals: list

4.4 Update a Goal: update

4.5 Remove a Goal: remove

4.6 Add a Habit: add

4.7 Change a Habit: change

4.8 Complete a Habit: done

4.9 Delete a Habit: delete

4.10 View all Habits: view

4.11 Return to Start-Up: return

4.12 Exit the Program: exit

5. About Loading and Saving Data

6. FAQ

7. Command Summary

8. Useful Links

Option 1: `About Ha(ppy)Bit`

Option 2: `User Guide`

Option 3: `Developer Guide`

Option 4: `Demo Video`

Option 5: `Start Application`

Option 6: `Exit Application`

4.1 Ask for Help: `help`

4.2 Set a Goal: `set`

4.3 List all Goals: `list`

4.4 Update a Goal: `update`

4.5 Remove a Goal: `remove`

4.6 Add a Habit: `add`

4.7 Change a Habit: `change`

4.8 Complete a Habit: `done`

4.9 Delete a Habit: `delete`

4.10 View all Habits: `view`

4.11 Return to Start-Up: `return`

4.12 Exit the Program: `exit`