D · Easy

Lesson 1 · On the house

Classes and inheritance

Reference-type classes, constructors, single inheritance, virtual methods by default, override, and super.

Lesson 2

Interfaces and abstract classes

interface declarations, implementing several, abstract methods, and final methods in interfaces.

Lesson 3

Templates

Function and struct templates, implicit instantiation, the ! syntax, and template value parameters.

Lesson 4

Ranges and std.algorithm

Lazy range pipelines with map, filter, reduce, sort, and chaining calls with UFCS.

Lesson 5

Exceptions and scope guards

throw, try/catch/finally, custom exceptions, enforce, and scope(exit/success/failure).

Lesson 6

Unit tests and contracts

unittest blocks, assert, in/out contracts, invariants, and running tests with -unittest.

Lesson 7

Delegates and lambdas

Function pointers vs delegates, closures that capture locals, passing callbacks, and std.functional.

Lesson 8

Operator overloading

opBinary, opUnary, opEquals, opCmp, opIndex, and opOpAssign on structs.

Lesson 9

Writing your own range

Implement an input range struct, make it infinite or finite, and plug it into Phobos algorithms.

Lesson 10

File I/O

std.file for whole files, std.stdio.File for streaming lines, writing, appending, and paths.