Java中的 LongStream count() 示例

LongStream count()返回流中元素的计数。 LongStream count() 存在于Java.util.stream.LongStream 中
句法 ：

long count()

示例 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);
    }
}

输出：

7

示例 2：计算给定范围内的元素。

// 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);
    }
}

输出：

48

示例 3：计算 LongStream 中的不同元素。

// 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);
    }
}

输出：

5