IntStream

allMatch

boolean allMatch (IntPredicate predicate)

Returns whether all elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

anyMatch

boolean anyMatch (IntPredicate predicate)

Returns whether any elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then false is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

asDoubleStream

DoubleStream asDoubleStream ()

Returns a DoubleStream consisting of the elements of this stream, converted to double.

This is an intermediate operation.

asLongStream

LongStream asLongStream ()

Returns a LongStream consisting of the elements of this stream, converted to long.

This is an intermediate operation.

average

OptionalDouble average ()

Returns an OptionalDouble describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty. This is a special case of a reduction.

This is a terminal operation.

boxed

Stream<Integer> boxed ()

Returns a Stream consisting of the elements of this stream, each boxed to an Integer.

This is an intermediate operation.

builder

IntStream.Builder builder ()

Returns a builder for an IntStream.

collect

R collect (Supplier<R> supplier, 
                ObjIntConsumer<R> accumulator, 
                BiConsumer<R, R> combiner)

Performs a mutable reduction operation on the elements of this stream. A mutable reduction is one in which the reduced value is a mutable result container, such as an ArrayList, and elements are incorporated by updating the state of the result rather than by replacing the result. This produces a result equivalent to:

R result = supplier.get();
     for (int element : this stream)
         accumulator.accept(result, element);
     return result;
 

Like reduce(int, IntBinaryOperator), collect operations can be parallelized without requiring additional synchronization.

This is a terminal operation.

concat

IntStream concat (IntStream a, 
                IntStream b)

Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked.

count

long count ()

Returns the count of elements in this stream. This is a special case of a reduction and is equivalent to:

return mapToLong(e -> 1L).sum();
 

This is a terminal operation.

distinct

IntStream distinct ()

Returns a stream consisting of the distinct elements of this stream.

This is a stateful intermediate operation.

empty

IntStream empty ()

Returns an empty sequential IntStream.

filter

IntStream filter (IntPredicate predicate)

Returns a stream consisting of the elements of this stream that match the given predicate.

This is an intermediate operation.

findAny

OptionalInt findAny ()

Returns an OptionalInt describing some element of the stream, or an empty OptionalInt if the stream is empty.

This is a short-circuiting terminal operation.

The behavior of this operation is explicitly nondeterministic; it is free to select any element in the stream. This is to allow for maximal performance in parallel operations; the cost is that multiple invocations on the same source may not return the same result. (If a stable result is desired, use findFirst() instead.)

findFirst

OptionalInt findFirst ()

Returns an OptionalInt describing the first element of this stream, or an empty OptionalInt if the stream is empty. If the stream has no encounter order, then any element may be returned.

This is a short-circuiting terminal operation.

flatMap

IntStream flatMap (IntFunction<? extends IntStream> mapper)

Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)

This is an intermediate operation.

forEach

void forEach (IntConsumer action)

Performs an action for each element of this stream.

This is a terminal operation.

For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization.

forEachOrdered

void forEachOrdered (IntConsumer action)

Performs an action for each element of this stream, guaranteeing that each element is processed in encounter order for streams that have a defined encounter order.

This is a terminal operation.

generate

IntStream generate (IntSupplier s)

Returns an infinite sequential unordered stream where each element is generated by the provided IntSupplier. This is suitable for generating constant streams, streams of random elements, etc.

iterate

IntStream iterate (int seed, 
                IntUnaryOperator f)

Returns an infinite sequential ordered IntStream produced by iterative application of a function f to an initial element seed, producing a Stream consisting of seed, f(seed), f(f(seed)), etc.

The first element (position 0) in the IntStream will be the provided seed. For n > 0, the element at position n, will be the result of applying the function f to the element at position n - 1.

iterator

PrimitiveIterator.OfInt iterator ()

Returns an iterator for the elements of this stream.

This is a terminal operation.

limit

IntStream limit (long maxSize)

Returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length.

This is a short-circuiting stateful intermediate operation.

map

IntStream map (IntUnaryOperator mapper)

Returns a stream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

mapToDouble

DoubleStream mapToDouble (IntToDoubleFunction mapper)

Returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

mapToLong

LongStream mapToLong (IntToLongFunction mapper)

Returns a LongStream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

mapToObj

Stream<U> mapToObj (IntFunction<? extends U> mapper)

Returns an object-valued Stream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

max

OptionalInt max ()

Returns an OptionalInt describing the maximum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to:

return reduce(Integer::max);
 

This is a terminal operation.

min

OptionalInt min ()

Returns an OptionalInt describing the minimum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to:

return reduce(Integer::min);
 

This is a terminal operation.

noneMatch

boolean noneMatch (IntPredicate predicate)

Returns whether no elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

of

IntStream of (int t)

Returns a sequential IntStream containing a single element.

of

IntStream of (int... values)

Returns a sequential ordered stream whose elements are the specified values.

parallel

IntStream parallel ()

Returns an equivalent stream that is parallel. May return itself, either because the stream was already parallel, or because the underlying stream state was modified to be parallel.

This is an intermediate operation.

peek

IntStream peek (IntConsumer action)

Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.

This is an intermediate operation.

For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization.

range

IntStream range (int startInclusive, 
                int endExclusive)

Returns a sequential ordered IntStream from startInclusive (inclusive) to endExclusive (exclusive) by an incremental step of 1.

rangeClosed

IntStream rangeClosed (int startInclusive, 
                int endInclusive)

Returns a sequential ordered IntStream from startInclusive (inclusive) to endInclusive (inclusive) by an incremental step of 1.

reduce

OptionalInt reduce (IntBinaryOperator op)

Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an OptionalInt describing the reduced value, if any. This is equivalent to:

boolean foundAny = false;
     int result = null;
     for (int element : this stream) {
         if (!foundAny) {
             foundAny = true;
             result = element;
         }
         else
             result = accumulator.applyAsInt(result, element);
     }
     return foundAny ? OptionalInt.of(result) : OptionalInt.empty();
 

The accumulator function must be an associative function.

This is a terminal operation.

reduce

int reduce (int identity, 
                IntBinaryOperator op)

Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value. This is equivalent to:

int result = identity;
     for (int element : this stream)
         result = accumulator.applyAsInt(result, element)
     return result;
 

The identity value must be an identity for the accumulator function. This means that for all x, accumulator.apply(identity, x) is equal to x. The accumulator function must be an associative function.

This is a terminal operation.

sequential

IntStream sequential ()

Returns an equivalent stream that is sequential. May return itself, either because the stream was already sequential, or because the underlying stream state was modified to be sequential.

This is an intermediate operation.

skip

IntStream skip (long n)

Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned.

This is a stateful intermediate operation.

sorted

IntStream sorted ()

Returns a stream consisting of the elements of this stream in sorted order.

This is a stateful intermediate operation.

spliterator

Spliterator.OfInt spliterator ()

Returns a spliterator for the elements of this stream.

This is a terminal operation.

sum

int sum ()

Returns the sum of elements in this stream. This is a special case of a reduction and is equivalent to:

return reduce(0, Integer::sum);
 

This is a terminal operation.

summaryStatistics

IntSummaryStatistics summaryStatistics ()

Returns an IntSummaryStatistics describing various summary data about the elements of this stream. This is a special case of a reduction.

This is a terminal operation.

toArray

int[] toArray ()

Returns an array containing the elements of this stream.

This is a terminal operation.