diff --git a/data/duke.txt b/data/duke.txt
index 89eb36c3e..e69de29bb 100644
--- a/data/duke.txt
+++ b/data/duke.txt
@@ -1,4 +0,0 @@
-T|X|coffee
-T| |coffee 2
-D| |coffee /by:  2pm
-E| |coffee again /from:  1pm /by:  2pm
diff --git a/src/main/java/Deadline.java b/src/main/java/Deadline.java
index 91ad8b295..627acc6c0 100644
--- a/src/main/java/Deadline.java
+++ b/src/main/java/Deadline.java
@@ -1,23 +1,24 @@
 public class Deadline extends Todo {
     protected String by;
+
+    /** Creates a deadline-type task, which contains a description and completion timing */
     public Deadline(String description, String by) {
         super(description);
         setBy(by);
     }
 
+    /** Sets the completion timing of the task */
     public void setBy(String by) {
         this.by = by;
     }
 
-    public String getBy() {
-        return this.by;
-    }
-
+    /** Returns type of task (deadline) */
     @Override
     public String getType() {
         return "deadline";
     }
 
+    /** Returns completion timing of task */
     @Override
     public String getTimings() {
         return this.by;
diff --git a/src/main/java/Event.java b/src/main/java/Event.java
index 14e565001..b87bac80b 100644
--- a/src/main/java/Event.java
+++ b/src/main/java/Event.java
@@ -1,21 +1,26 @@
 public class Event extends Task{
     protected String start;
     protected String end;
+
+    /** Creates an event-type task, which contains a description and start and end timing */
     public Event(String description, String start, String end) {
         super(description);
         setStartEnd(start, end);
     }
 
+    /** Sets the start and end timing of the task */
     public void setStartEnd (String start, String end) {
         this.start = start;
         this.end = end;
     }
 
+    /** Returns type of task (event) */
     @Override
     public String getType() {
         return "event";
     }
 
+    /** Returns start and end timing as a single string, separated by a slash */
     @Override
     public String getTimings() {
         return this.start + "/" + this.end;
diff --git a/src/main/java/Parser.java b/src/main/java/Parser.java
index c8f4658a7..6656494d6 100644
--- a/src/main/java/Parser.java
+++ b/src/main/java/Parser.java
@@ -2,6 +2,7 @@
 
 public class Parser {
 
+    /** Parses user command and calls relevant functions */
     public static void parseCommand(String taskInfo, ArrayList<Task> tasks) {
         if (taskInfo.equals("list")) {
             getList(tasks);
@@ -53,12 +54,14 @@ public static void parseCommand(String taskInfo, ArrayList<Task> tasks) {
         }
     }
 
+    /** Prints list of all tasks */
     public static void getList(ArrayList<Task> tasks) {
         for (int i = 0; i < tasks.size(); i++) {
             System.out.println((i + 1) + "." + Ui.printTask(tasks.get(i)));
         }
     }
 
+    /** Finds tasks based on a specific keyword */
     public static void findTask(ArrayList<Task> tasks, String taskDescription) {
         int taskNo = 0;
         for (Task task: tasks) {
diff --git a/src/main/java/Storage.java b/src/main/java/Storage.java
index 7a87f3c29..4a805cdbb 100644
--- a/src/main/java/Storage.java
+++ b/src/main/java/Storage.java
@@ -10,6 +10,7 @@
 public class Storage {
     private static final String FILEPATH = "data/duke.txt";
 
+    /** Writes tasks to file after user exits */
     static void writeToFile(ArrayList<Task> tasks) throws IOException {
         Files.createDirectories(Paths.get("./data"));
         try {
@@ -48,6 +49,7 @@ static void writeToFile(ArrayList<Task> tasks) throws IOException {
 
     }
 
+    /** Loads tasks from previous save files when starting Duke */
     static ArrayList<Task> loadFromFile() {
         ArrayList<Task> tasks = new ArrayList<Task>();
 
diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index 9cb71c904..b03e6af1e 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -3,28 +3,34 @@ public abstract class Task {
     protected boolean isDone;
     protected String type;
 
+    /** Creates a task, which must contain a description */
     public Task(String description) {
         this.description = description;
         this.isDone = false;
     }
 
+    /** Returns whether a task is complete or incomplete */
     public String getStatusIcon() {
         // mark done task with X
         return (isDone ? "X" : " ");
     }
 
+    /** Marks a task as done */
     public void markAsDone(){
         isDone = true;
     }
 
+    /** Marks a task as not done */
     public void unmarkAsDone(){
         isDone = false;
     }
 
+    /** Returns type of task */
     public String getType() {
         return null;
     }
 
+    /** Returns relevant timings of task, if any */
     public String getTimings() {
         return null;
     }
diff --git a/src/main/java/Tasklist.java b/src/main/java/Tasklist.java
index 306d63c70..d115288c5 100644
--- a/src/main/java/Tasklist.java
+++ b/src/main/java/Tasklist.java
@@ -5,12 +5,14 @@ public class Tasklist {
     private static final int FROM_LEN = 6;
     private static final int BY_LEN = 4;
 
+    /** Adds a todo-type task */
     static void addTodo(ArrayList<Task> tasks, String taskDescription) {
         Task newTodo = new Todo(taskDescription);
         tasks.add(newTodo);
         System.out.println("Created todo: " + Ui.printTask(newTodo));
     }
 
+    /** Adds a deadline-type task */
     static void addDeadline(ArrayList<Task> tasks, String taskDescription) {
         int deadlineByIndex = taskDescription.indexOf("/");
 
@@ -22,6 +24,7 @@ static void addDeadline(ArrayList<Task> tasks, String taskDescription) {
         System.out.println("Created deadline: " + Ui.printTask(newDeadline));
     }
 
+    /** Adds an event-type task */
     static void addEvent(ArrayList<Task> tasks, String taskDescription) {
         int eventStartIndex = taskDescription.indexOf("/");
         int eventEndIndex = taskDescription.lastIndexOf("/");
@@ -36,14 +39,17 @@ static void addEvent(ArrayList<Task> tasks, String taskDescription) {
 
     }
 
+    /** Mark a task as complete */
     static void markTask(ArrayList<Task> tasks, int taskNo) {
         tasks.get(taskNo).markAsDone();
     }
 
+    /** Mark a task as incomplete */
     static void unmarkTask(ArrayList<Task> tasks, int taskNo) {
         tasks.get(taskNo).unmarkAsDone();
     }
 
+    /** Delete a task by task number */
     static void deleteTask(ArrayList<Task> tasks, int taskNo) {
         if (tasks.size() > 0) {
             System.out.println("Got it! This task will be removed:");
diff --git a/src/main/java/Todo.java b/src/main/java/Todo.java
index 19c2d24bb..5b48ea5f9 100644
--- a/src/main/java/Todo.java
+++ b/src/main/java/Todo.java
@@ -1,10 +1,13 @@
 public class Todo extends Task {
     protected boolean isDone;
+
+    /** Creates a todo-type task, which contains a description */
     public Todo(String description) {
         super(description);
         isDone = false;
     }
 
+    /** Returns type of task (todo) */
     @Override
     public String getType() {
         return "todo";
diff --git a/src/main/java/Ui.java b/src/main/java/Ui.java
index fa6cc83c4..2924c1b63 100644
--- a/src/main/java/Ui.java
+++ b/src/main/java/Ui.java
@@ -2,6 +2,7 @@
 
 public class Ui {
 
+    /** Display message when loading previously saved tasks */
     static void loadDataMessage() {
         System.out.println(("Loading previous save data..."));
     }
@@ -15,11 +16,13 @@ static void goodbyeMessage() {
         System.out.println("Bye! :D");
     }
 
+    /** Reads the next user command */
     static String readCommand() {
         Scanner reader = new Scanner(System.in);
         return reader.nextLine();
     }
 
+    /** Format printing of task by task type */
     static String printTask(Task task) {
         String taskType = task.getType();
         String formattedTask;