SOLID = 5 OO design principles. S (Single Responsibility): a class/module has one responsibility (one job) and should change for one reason. O (Open/Closed): extend without modifying existing code. L (Liskov Substitution): subtypes are safely substitutable (keep the contract). I (Interface Segregation): small focused interfaces, no unused methods. D (Dependency Inversion): depend on abstractions; inject implementations (DI).
Advanced answer
Deep dive
Expanding on the short answer — what usually matters in practice:
Explain the "why", not just the "what" (intuition + consequences).
Trade-offs: what you gain/lose (time, memory, complexity, risk).
Edge cases: empty inputs, large inputs, invalid inputs, concurrency.
Examples
A tiny example (an explanation template):
// Example: discuss trade-offs for "explain-solid-principles."
function explain() {
// Start from the core idea:
// SOLID is a set of OOP design principles: Single Responsibility (one reason to change), Ope
}
Common pitfalls
Too generic: no concrete trade-offs or examples.
Mixing average-case and worst-case (e.g., complexity).