Intermediate Operations

Intermediate operations are the transformations chained on a stream before a terminal operation kicks them off. Each one returns a new stream and runs lazily, so the work happens once the terminal operation pulls. The previous lesson covered how operations are categorized (intermediate vs terminal, stateful vs stateless, short-circuiting). This lesson walks through every common intermediate operation, what its signature looks like, when to use it, and the pitfalls that show up in real code.