Java 中的 LongStream count()，示例
原文:https://www . geesforgeks . org/longstream-count-Java-examples/
LongStream count() 返回流中元素的计数。LongStream count()存在于 Java . util . stream . LongStream 语法:
long count()
例 1 : 计算 LongStream 中的元素。
// Java code for LongStream count()
// to count the number of elements in
// given stream
import java.util.*;
import java.util.stream.LongStream;
class GFG {
// Driver code
public static void main(String[] args)
{
// creating a stream
LongStream stream = LongStream.of(2L, 3L, 4L, 5L,
6L, 7L, 8L);
// storing the count of elements
// in a variable named total
long total = stream.count();
// displaying the total number of elements
System.out.println(total);
}
}
Output:
7
例 2 : 统计给定范围内的元素。
// Java code for LongStream count()
// to count the number of elements in
// given range excluding the last element
import java.util.*;
import java.util.stream.LongStream;
class GFG {
// Driver code
public static void main(String[] args)
{
// creating a stream
LongStream stream = LongStream.range(2, 50);
// storing the count of elements
// in a variable named total
long total = stream.count();
// displaying the total number of elements
System.out.println(total);
}
}
Output:
48
例 3 : 计算 LongStream 中不同的元素。
// Java code for LongStream count()
// to count the number of distinct
// elements in given stream
import java.util.*;
import java.util.stream.LongStream;
class GFG {
// Driver code
public static void main(String[] args)
{
// creating a stream
LongStream stream = LongStream.of(2L, 3L, 4L, 4L,
7L, 7L, 8L);
// storing the count of distinct elements
// in a variable named total
long total = stream.distinct().count();
// displaying the total number of elements
System.out.println(total);
}
}
Output:
5
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