程序包 java.util

类 IntSummaryStatistics

java.lang.Object

java.util.IntSummaryStatistics

所有已实现的接口:

IntConsumer

public class IntSummaryStatistics
extends Object
implements IntConsumer

A state object for collecting statistics such as count, min, max, sum, and average.

This class is designed to work with (though does not require) streams. For example, you can compute summary statistics on a stream of ints with:

 
 IntSummaryStatistics stats = intStream.collect(IntSummaryStatistics::new,
                                                IntSummaryStatistics::accept,
                                                IntSummaryStatistics::combine);
 

IntSummaryStatistics can be used as a reduction target for a stream. For example:

 
 IntSummaryStatistics stats = people.stream()
                                    .collect(Collectors.summarizingInt(Person::getDependents));

This computes, in a single pass, the count of people, as well as the minimum, maximum, sum, and average of their number of dependents.

从以下版本开始:

1.8

构造器概要

构造器

构造器	说明
IntSummaryStatistics()	Construct an empty instance with zero count, zero sum, Integer.MAX_VALUE min, Integer.MIN_VALUE max and zero average.

方法概要

限定符和类型	方法	说明
void	accept(int value)	Records a new value into the summary information
void	combine(IntSummaryStatistics other)	Combines the state of another IntSummaryStatistics into this one.
double	getAverage()	Returns the arithmetic mean of values recorded, or zero if no values have been recorded.
long	getCount()	Returns the count of values recorded.
int	getMax()	Returns the maximum value recorded, or Integer.MIN_VALUE if no values have been recorded.
int	getMin()	Returns the minimum value recorded, or Integer.MAX_VALUE if no values have been recorded.
long	getSum()	Returns the sum of values recorded, or zero if no values have been recorded.
String	toString()	Returns a string representation of the object.

从接口继承的方法 java.util.function.IntConsumer

andThen

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

构造器详细资料

IntSummaryStatistics

public IntSummaryStatistics()

Construct an empty instance with zero count, zero sum, Integer.MAX_VALUE min, Integer.MIN_VALUE max and zero average.

方法详细资料

accept

public void accept(int value)

Records a new value into the summary information

指定者:

accept 在接口中 IntConsumer

参数:

value - the input value

combine

public void combine(IntSummaryStatistics other)

Combines the state of another IntSummaryStatistics into this one.

参数:

other - another IntSummaryStatistics

抛出:

NullPointerException - if other is null

getCount

public final long getCount()

Returns the count of values recorded.

返回:

the count of values

getSum

public final long getSum()

Returns the sum of values recorded, or zero if no values have been recorded.

返回:

the sum of values, or zero if none

getMin

public final int getMin()

Returns the minimum value recorded, or Integer.MAX_VALUE if no values have been recorded.

返回:

the minimum value, or Integer.MAX_VALUE if none

getMax

public final int getMax()

Returns the maximum value recorded, or Integer.MIN_VALUE if no values have been recorded.

返回:

the maximum value, or Integer.MIN_VALUE if none

getAverage

public final double getAverage()

Returns the arithmetic mean of values recorded, or zero if no values have been recorded.

返回:

the arithmetic mean of values, or zero if none

toString

public String toString()

从类复制的说明: Object

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

覆盖:

toString 在类中 Object

返回:

a string representation of the object.