🧵 Interfaces in Java, explained like you're 5!
1️⃣ Imagine a Pizza Menu 🍕
You walk into a pizza place and see a menu. The menu promises what pizzas they offer—but doesn’t make them yet.
An interface in Java is like that menu: it defines what a class should do, but not how!
2️⃣ The Chef’s Contract 📝
The menu says:
- "All pizzas must have cheese 🧀"
- "All pizzas must be bakeable 🔥" Any chef (class) who follows this menu must fulfill these rules! In Java, we call this "implementing an interface."
3️⃣ Multiple Menus, One Chef!
A chef can follow multiple menus (interfaces):
- Italian food menu 🍝
- Fast food menu 🍔 Similarly, a Java class can implement many interfaces at once! (Unlike inheritance, where you only get one parent.)
4️⃣ But… What If the Chef Cheats? 😱
If a chef says, "I’ll follow the pizza menu!" but doesn’t add cheese… BIG PROBLEM!
Java won’t allow this—it forces the class to implement every method in the interface, or the code won’t compile!
5️⃣ Default Recipes 🍳 (Java 8+ Magic!)
What if some pizzas usually have tomato sauce, but not always?
Interfaces can now provide default methods—like a "standard recipe" that chefs can override if they want!
java
interface Pizza {
default void addSauce() { System.out.println("Adding tomato sauce!"); }
}