Java 中的流过滤器()，示例
原文:https://www.geeksforgeeks.org/stream-filter-java-examples/
流过滤器(谓词谓词)返回一个由该流中与给定谓词匹配的元素组成的流。这是一个 的中级操作。 这些操作总是懒惰的，即执行诸如 filter()的中间操作实际上并不执行任何过滤，而是创建一个新的流，当遍历该流时，它包含与给定谓词匹配的初始流的元素。
语法:
Stream<**T**> filter(Predicate<**?** super **T**> predicate)
Where, Stream is an interface and T is the
type of the input to the predicate.
The function returns the new stream.
示例 1 : 过滤()方法，具有过滤掉可被 5 整除的元素的操作。
// Java code for Stream filter
// (Predicate predicate) to get a stream
// consisting of the elements of this
// stream that match the given predicate.
import java.util.*;
class GFG {
// Driver code
public static void main(String[] args)
{
// Creating a list of Integers
List<Integer> list = Arrays.asList(3, 4, 6, 12, 20);
// Using Stream filter(Predicate predicate)
// to get a stream consisting of the
// elements that are divisible by 5
list.stream().filter(num -> num % 5 == 0).forEach(System.out::println);
}
}
输出:
20
示例 2 : filter()方法，操作是过滤掉索引 1 处带有大写字母的元素。
// Java code for Stream filter
// (Predicate predicate) to get a stream
// consisting of the elements of this
// stream that match the given predicate.
import java.util.stream.Stream;
class GFG {
// Driver code
public static void main(String[] args)
{
// Creating a Stream of Strings
Stream<String> stream = Stream.of("Geeks", "fOr",
"GEEKSQUIZ", "GeeksforGeeks");
// Using Stream filter(Predicate predicate)
// to get a stream consisting of the
// elements having UpperCase Character
// at index 1
stream.filter(str -> Character.isUpperCase(str.charAt(1)))
.forEach(System.out::println);
}
}
输出:
fOr
GEEKSQUIZ
示例 3 : 过滤()方法，过滤掉以 s 结尾的元素
// Java code for Stream filter
// (Predicate predicate) to get a stream
// consisting of the elements of this
// stream that match the given predicate.
import java.util.stream.Stream;
class GFG {
// Driver code
public static void main(String[] args)
{
// Creating a Stream of Strings
Stream<String> stream = Stream.of("Geeks", "foR",
"GeEksQuiz", "GeeksforGeeks");
// Using Stream filter(Predicate predicate)
// to get a stream consisting of the
// elements ending with s
stream.filter(str -> str.endsWith("s"))
.forEach(System.out::println);
}
}
输出:
Geeks
GeeksforGeeks
版权属于：月萌API www.moonapi.com，转载请注明出处
