Justin MacArthur
Advanced coding mentor, let me help you to master programming in all of it's aspects.
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Justin MacArthur
Diploma degree
/ 55 min
About your coding tutor - Justin
Hi, I’m Justin. I’ve been coding professionally since 2005 and teaching since 2020. I specialize in helping students build programming as a practical, transferable skill, not just memorize syntax. My experience spans C/C++, C#, Java, Python, PHP, JavaScript, and TypeScript, with projects in web development, mobile apps, video games, and custom system software. I’ve taught learners at every level, from beginners writing their first lines of code to experienced developers sharpening specific skills. My lessons are tailored to your goals, pace, and learning style, so you can build confidence while solving real problems instead of getting stuck in theory alone. I can help with computer science fundamentals, debugging, project planning, object-oriented programming, algorithms, data structures, games, websites, and understanding how different technologies fit together. I like to make lessons practical, patient, and encouraging, with enough challenge to help you grow without feeling overwhelmed. Whether you’re preparing for a class, building a portfolio project, improving at work, or starting your computer science journey from scratch, I’d be happy to help you strengthen your skills and discover the coder you’re meant to become.
Coding tutor specialities
Debugging
Job readiness
Exam prep
Paired coding
Code Review
Project help
Code Optimization
CoTutorAI modules
Summary
Podcast
Quiz
Learnings
Flashcard
Spotlight
Zero Risk Guaranteed
15-days refund
Free tutor swap
No cancel fee
1-yr validity
24/7 support
Learner types for coding classes
Coding for intermediate
Coding for adults
Coding for advanced
Coding for beginners
Improved problem-solving skills
92% of students report faster problem-solving after lessons.
Project-based learning for real-world skills
90% of students complete relevant coding projects.
Focused on real-world coding applications
Build real projects, from apps to websites.
Justin - Coding tutor also teaches
C
C++
CSS
HTML
Java
JavaScript
Coding concepts taught by Justin
The Student and Tutor worked on two core programming tasks: implementing internationalization for UI elements in a Java application and defining an Antler grammar for a hotkey DSL. The Tutor demonstrated a solution for i18n and guided the Student through structuring the Antler grammar. The Tutor will send the complete code, including a fix for Antler parsing issues, and the Student can book a follow-up lesson.
Internationalization (I18n) Implementation in Java
Defining Domain Specific Languages (DSLs) with Antler
Integrating Antler with the Gradle Build System
Student and Tutor worked on a Java programming assignment for a text editor. They implemented `openFile` and `saveFile` functionality using `JFileChooser`, then set up a Gradle project in VS Code and migrated the existing code. The Student plans to work on internationalization and domain-specific language (DSL) parsing for key mappings as homework and will reconvene for further guidance on Saturday.
Java File Operations with JFileChooser (Swing)
Setting Up a Gradle Project in VS Code
Introduction to Internationalization (i18n)
Implementing Domain Specific Languages (DSL) for Key Mappings
Planning for a Plugin Architecture
The Student and Tutor reviewed advanced Java concepts related to plugin systems and extensible design, including the use of APIs, reflection, JAR files, and annotations. The Tutor explained how these elements facilitate adding modular functionality to software. The Student was advised to focus on specific sections of their notes for an upcoming assignment and to practice by building a simple plugin system.
Plugin Interfaces and Functionality
Scripting as an Extensibility Method
Annotations for Simplified Plugin Integration
Dynamic Plugin Loading with Reflection
Modular Design: Core vs. External Plugins
Extensible Design & Plugins
The Student and Tutor reviewed current and past data analysis assignments, specifically focusing on the challenges of interpreting and presenting AI-generated insights from a sleep health analysis dataset. The Tutor provided practical advice on using AI tools more effectively to explain data derivations and identify potential areas for deeper analysis. The Student plans to restructure their presentation based on the discussion and send it to the Tutor for review.
Ethical AI Use in Academic Assignments
Simplifying Complex Statistical Analysis
Strategic Data Exploration and Presentation
Leveraging AI for Explanation and Derivation
Interpreting Core Findings from Health Data
Student and Tutor reviewed an AI-generated data analysis for a university assignment, focusing on correlation coefficients, regression analysis, and the distinction between independent and dependent variables. Student practiced generating and interpreting scatter plots with linear regressions for various data relationships. The Student plans to submit the assignment and schedule a follow-up session to continue learning these concepts.
Pearson's R: The Correlation Coefficient
AI-Powered Initial Data Analysis
Independent vs. Dependent Variables
Visualizing Data with Scatter Plots and Regression Lines
Regression Analysis Fundamentals
The Student and Tutor reviewed an experimental design for a homework assignment, focusing on identifying and mitigating endogeneity and threats to validity in a natural experiment concerning retirement and mortality. They discussed strategies for controlling confounding variables and the differences between natural and controlled experiments. The session concluded with the Student selecting a dataset for the next assignment (gym member exercise data from Kaggle) and planning how to formulate a research question and conduct basic descriptive statistics.
Natural vs. Designed Experiments
Data Set Selection for Analysis
Formulating Research Questions from Data Features
Endogeneity and Threats to Validity
Independent
Dependent
and Confounding Variables
Mitigating Threats to Validity in Natural Experiments
Approach & tools used by coding tutor
Android Studio
Visual Studio Code
Git & GitHub
Jupyter Notebook
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