Java reference

Stream.dropWhile()

Drops elements while a condition holds and passes on everything after.

Available since: Java 9

Syntax

default Stream<T> dropWhile(Predicate<? super T> predicate)

Parameters

Parameter	Type	Description
predicate	Predicate<? super T>	While this condition is true, elements are dropped.

Return value

Stream<T>The rest of the stream from the first element that fails the condition.

Examples

Skipping header lines:

void main() {
    List<String> lines = List.of("# title", "# author", "first line", "# not a header", "last line");
    lines.stream()
        .dropWhile(l -> l.startsWith("#"))
        .forEach(IO::println);
}

Output:

first line
# not a header
last line

Notes

After the first non-matching element the condition is not checked any more — that is why the # not a header line stayed. It is the mirror counterpart of takeWhile().

In the tutorial

Stream operations — The main Stream API operations — filter, map, sorted, distinct, limit, skip, count, reduce, anyMatch, findFirst and numeric streams.

Thanks for reading!