🔹 1. Collecting Results
| Method | Description |
|---|
collect() | Accumulates elements into a collection (like List, Set, Map) |
toArray() | Converts the stream into an array |
Example:
List<String> result = stream.collect(Collectors.toList());
🔹 2. Iterating / Consuming Elements
| Method | Description |
|---|
forEach() | Performs an action for each element (order not guaranteed in parallel) |
forEachOrdered() | Like forEach, but maintains encounter order |
Example:
stream.forEach(System.out::println);
🔹 3. Reducing / Aggregating
| Method | Description |
|---|
reduce() | Combines elements into a single result (e.g., sum, min, max) |
count() | Returns the number of elements |
sum(), average() | For numeric streams (IntStream, etc.) |
min(), max() | Finds the minimum/maximum element |
Example:
int total = stream.reduce(0, Integer::sum);
🔹 4. Matching and Searching
| Method | Description |
|---|
anyMatch() | Returns true if any element matches the condition |
allMatch() | Returns true if all elements match the condition |
noneMatch() | Returns true if no elements match the condition |
findFirst() | Returns the first element (optional) |
findAny() | Returns any element (useful in parallel streams) |
Example:
boolean hasNegative = stream.anyMatch(x -> x < 0);
🔹 5. Short-Circuiting
Some terminal methods are also short-circuiting, meaning they don’t need to process the entire stream:
findFirst(), findAny()anyMatch(), allMatch(), noneMatch()limit(n) (technically intermediate but works with short-circuiting terminal methods)
🧠 Summary
| Category | Methods |
|---|
| Collection | collect(), toArray() |
| Iteration | forEach(), forEachOrdered() |
| Reduction | reduce(), count(), sum(), min(), max(), average() |
| Matching | anyMatch(), allMatch(), noneMatch(), findFirst(), findAny() |
