PHP Questions

Q: Can you explain the difference between == and === in PHP?

• Junior:
  • == is loose equality, === is strict equality (checks value and type).
  • Example: "1" == 1 is true, "1" === 1 is false.
• Mid:
  • Discuss PHP’s loosely typed nature and potential pitfalls of ==.

Q: What is the purpose of isset() and empty() functions in PHP, and what's the difference?

• Junior:
  • isset() checks if a variable is set and not null.
  • empty() checks if a variable is type-specific empty (0, "", null, etc.).
• Mid:
  • Notes nuances, such as isset() not working for unset array keys, and how empty() evaluates several falsie values.

Q: How would you handle errors and exceptions in PHP?

• Junior:
  • Use try-catch for exceptions.
  • error_reporting() to set PHP error levels.
• Mid:
  • Differentiates between exceptions and errors (runtime vs. fatal).
  • Implement error handling with try-catch and custom error handlers using set_error_handler().
  • Consider finally blocks for cleanup, error_log() for logging errors.
• Senior:
  • Discusses best practices for logging, debugging, and using frameworks that provide error handling mechanisms.

Q: What is the difference between a public, private, and protected method in PHP?

• Junior:
  • public is accessible everywhere, private is accessible only within the class,protected is accessible within the class and subclasses.
• Mid:
  • Discusses inheritance and class extentions.
• Senior:
  • Explains encapsulation, security, and design patterns that utilize different access levels.
  • Explain difficulties in testing of private