What Are Design Patterns

What Are Design Patterns

In this lesson — part of Pattern Foundations — you'll learn what are design patterns in Objective-C and why it matters in real work.

Why it matters

Patterns are proven solutions to recurring design problems — a shared vocabulary for teams.

Key ideas

• Creational, structural, behavioral
• When (and when not) to use a pattern
• Common patterns
• Patterns as communication

In practice

Here's the idea in pseudocode — the exact syntax varies by language:

// Objective-C: factory
function create(type) { ... }

Try it yourself

Exercise: In Objective-C, refactor a big switch statement using the Strategy pattern.

Recap

You now understand what are design patterns and can apply it in Objective-C. Mark this lesson complete and continue to the next one.