- Foreach
1. What is forEach? Imagine you are a teacher handing back graded papers. You pick up each paper from the stack, call the student’s name, and hand it over. You do not care about the paper’s position in the stack — you just process each one in order until the stack is empty. That is […]
- Streams
1. What is the Stream API? Think of a conveyor belt in a sushi restaurant. Plates of sushi travel along the belt, and you — the customer — pick only the ones you want, maybe add some soy sauce, and eat them. You never rearrange the kitchen. You never touch the plates you skip. You […]
- Interface default methods and static methods
1. Why Default Methods? Imagine a city planner who designed a road system 20 years ago. Thousands of buildings were constructed along those roads. Now the city needs bike lanes. The planner cannot tear down every building and start over — the city must add bike lanes without breaking the existing…
- Functional Interfaces
1. What is a Functional Interface? Imagine a contract that says: “You must do exactly one thing.” It does not care what that thing is — it could be filtering data, transforming text, printing output, or computing a value. But the contract only has one obligation. That is a functional interface in…
- Method References
1. What Are Method References? Imagine you are giving someone directions. You could say: “Walk to the kitchen, open the drawer, grab a knife, and cut the bread.” Or you could simply say: “Cut the bread” — because the person already knows the steps. A method reference is that shorter instruction.…