带有示例的 Java . util . longsummarystatistics 类

原文:https://www . geesforgeks . org/Java-util-longsummarystatistics-class-with-examples/

LongSummaryStatistics 类存在于 java.util 包 中。它收集了 Long 对象,在我们处理大整数流的情况下非常有用。它维护已处理的值的数量、它们的总和以及各种其他统计信息的计数。该类也可以与 Streams 一起使用。

它是有用的,因为它保持一个连续的总和、平均值等。因此可以用于统计数据的处理。

等级体系

java.lang.Object
 java.util.LongSummaryStatistics

施工人员

  1. LongSummaryStatistics() :默认构造函数,将计数和求和初始化为零,将 max 设置为 Long。MIN_VALUE 和 MIN 至长。最大值

    ```java public LongSummaryStatistics()

    ```

方法:

  1. accept() :函数重载,将传递的整数或长值加入统计数据。

    ```java public void accept(int value) public void accept(long value)

    ```

  2. combine() :该函数将传递的 LongSummaryStatistics 对象的统计数据与当前统计数据进行合并。

    ```java public void combine(LongSummaryStatistics other)

    ```

  3. getCount() :返回已处理的长值数的计数。

    ```java public final long getCount()

    ```

  4. getSum() :返回所有已处理长值的总和。

    ```java public final long getSum()

    ```

  5. getAverage() :返回所有已处理长值的平均值。

    ```java public final double getAverage()

    ```

  6. getMin() :返回所有已处理长值的最小整数。

    ```java public final long getMin()

    ```

  7. getMax() :返回所有已处理长值的最大整数。

    ```java public final long getMax()

    ```

  8. toString(): Returns the string representation of all the statistical data contained in the object.

    ```java public String toString()

    ```

    示例演示 LongSummaryStatistics 在运行。

    ```java // Java program to demonstrate // LongSummaryStatistics class

    import java.util.*;

    public class LongSummaryStatisticsDemo {     public static void main(String[] args)     {         LongSummaryStatistics longSummaryStatistics             = new LongSummaryStatistics();         List list = new LinkedList<>();         list.add(100l);         list.add(200l);         list.add(300l);         list.add(400l);         list.add(500l);         list.add(600l);         list.add(700l);         list.add(800l);         list.add(900l);         list.add(1000l);

    Iterator iterator = list.listIterator();         while (iterator.hasNext()) {             // Add the values to the LongSummaryStatistics object             longSummaryStatistics.accept(iterator.next());         }

    // Use various methods to obtain the data         System.out.println("The count of values is "                            + longSummaryStatistics.getCount());         System.out.println("The average of values is "                            + longSummaryStatistics.getAverage());         System.out.println("The sum of values is "                            + longSummaryStatistics.getSum());         System.out.println("The maximum of values is "                            + longSummaryStatistics.getMax());         System.out.println("The minimum of values is "                            + longSummaryStatistics.getMin());         System.out.println("The string representation is ");         System.out.println(longSummaryStatistics.toString());     } } ```

    Output:

    ```java The count of values is 10 The average of values is 550.0 The sum of values is 5500 The maximum of values is 1000 The minimum of values is 100 The string representation is LongSummaryStatistics{count=10, sum=5500, min=100, average=550.000000, max=1000}

    ```

    参考:https://docs . Oracle . com/javase/9/docs/API/Java/util/longsummarystatistics . html