java-collections

Java Collections Framework Learning Guide

This repository is designed to help you learn the Java Collections Framework step-by-step. Each section introduces a new concept, provides examples, and gives you practice problems to reinforce what you learned.

Your goal is to work through the folders in order. Each folder contains:

• README.md → Explanation of the concept
• Examples / Demo Code → Working examples to study
• Practice Problems → Exercises for you to complete

Follow the steps below to complete the assignment.

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Learning Path

Work through the following sections in this exact order.

1. Hierarchy

Start by understanding the structure of the Java Collections Framework.

In this section:

• Read the README.md
• Review the hierarchy notes
• Run the example code
• Complete the practice questions

This section will help you understand how everything connects together.

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2. Iterable

Next, learn about Iterable, the root interface of the collections framework.

Focus on:

• How iteration works
• How enhanced for-loops work
• The role of Iterator

Steps:

1. Read the README
2. Study the demo code
3. Complete the practice exercises

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3. Collection

This section introduces the Collection interface, which is the parent of most collection types.

Key concepts:

• Common collection methods
• Shared behavior across lists, sets, and queues

Steps:

1. Read the README
2. Study the examples
3. Complete the practice problems

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4. Lists

Lists store ordered collections of elements and allow duplicates.

Structures covered include:

• ArrayList
• LinkedList
• Vector
• Stack

Steps:

1. Read the README for each list implementation
2. Study the demo code
3. Complete the practice problems

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5. Sets

Sets store unique elements and do not allow duplicates.

Structures covered include:

• HashSet
• LinkedHashSet
• TreeSet

Steps:

1. Read the README for each set implementation
2. Study the demo code
3. Complete the practice problems

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6. Queues

Queues process elements in order, typically using FIFO (First-In, First-Out) behavior.

Structures covered include:

• Queue
• Deque
• ArrayDeque
• PriorityQueue

Steps:

1. Read the README for each queue structure
2. Study the demo code
3. Complete the practice problems

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7. Maps

Maps store key-value pairs.

Structures covered include:

• HashMap
• LinkedHashMap
• TreeMap

Steps:

1. Read the README for each map implementation
2. Study the demo code
3. Complete the practice problems

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Final Step: HackerRank Problems

After completing all sections, you will solve 10 HackerRank-style problems related to collections.

These problems are designed to test your ability to:

• Choose the correct data structure
• Use collections effectively
• Solve real-world coding problems

Complete all problems in the provided Java file.

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Tips for Success

• Work through the sections in order
• Run the example code to see how each structure behaves
• Try solving practice problems before looking up solutions
• Focus on understanding when to use each collection

By the end of this assignment, you should understand how to work with:

• Lists
• Sets
• Queues
• Maps

and how they fit into the Java Collections Framework.