Comprehensive Guide to Common PHP Interview Topics and Questions

Overview of PHP Interview Focus Areas

PHP interviews typically assess a candidate’s understanding of language fundamentals, framework usage, project experience, and problem-solving abilities. Interviewers often evaluate not only coding skills but also architectural thinking, performance tuning, and security awareness.

Core Knowledge Areas

Basic syntax and language features are among the most frequently tested aspects in PHP interviews. Common topics include:

• PHP syntax and data types
• Variables, arrays, objects, and classes
• Control flow statements and function creation
• File handling and database interactions

Object-Oriented Programming (OOP)

OOP is a core concept in PHP development, and many questions focus on both theoretical and practical understanding:

• Class and object definitions and usage
• Inheritance, polymorphism, and encapsulation
• Abstract classes and interfaces
• Common design patterns such as Singleton, Factory, and Observer

Frameworks and Tools

Modern PHP development often involves frameworks and tools, so interview questions may include:

• MVC architecture principles and implementation
• Popular frameworks such as Laravel and CodeIgniter
• Object-relational mapping (ORM) and SQL optimization
• Version control (Git) and deployment tools (Docker)

Performance Optimization and Error Handling

Performance and reliability are key evaluation criteria in interviews. Topics may include:

• Caching strategies and load balancing
• Database indexing and query optimization
• Code performance tuning and exception handling

Security Practices

Security is a major concern in PHP projects. Common security-related questions include:

• Preventing cross-site scripting (XSS) and SQL injection
• Password hashing and session management
• Authentication and authorization techniques

Problem-Solving and Algorithm Skills

Beyond theoretical knowledge, interviewers value how candidates think and approach challenges:

• Debugging and troubleshooting techniques
• Understanding of basic algorithms and data structures
• Developing practical solutions for real-world business problems

Project Experience and Soft Skills

Project experience often reflects a developer’s practical capabilities and teamwork skills. Interviewers may ask about:

• Past PHP projects and specific responsibilities
• Collaboration and communication skills
• Familiarity with the PHP ecosystem and technology trends

Conclusion

To prepare for a PHP interview, candidates should focus on solidifying their fundamental knowledge while building hands-on project experience. Systematic study and reflection will help you demonstrate both technical expertise and strategic thinking during interviews.