Java IntStream max()与实例

Java 8中的java.util.stream.IntStream，处理原始的ints。它有助于以一种新的方式解决诸如寻找数组中的最大值、寻找数组中的最小值、数组中所有元素的总和以及数组中所有值的平均值等问题。 IntStream max() 返回一个OptionalInt，描述此流的最大元素，如果此流为空，则返回一个空的Optional。

语法:

OptionalInt() max()

其中，OptionalInt是一个容器对象
可能包含也可能不包含一个int值。

例1 :

// Java code for IntStream max()
import java.util.*;
import java.util.stream.IntStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
  
        // creating a stream
        IntStream stream = IntStream.of(-9, -18, 54, 8, 7, 14, 3);
  
        // OptionalInt is a container object
        // which may or may not contain a
        // int value.
        OptionalInt obj = stream.max();
  
        // If a value is present, isPresent() will
        // return true and getAsInt() will
        // return the value
        if (obj.isPresent()) {
            System.out.println(obj.getAsInt());
        }
        else {
            System.out.println("-1");
        }
    }
}

输出:

例2 :

// Java code for IntStream max()
// to get the maximum value in range
// excluding the last element
import java.util.*;
import java.util.stream.IntStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
  
        // To find maximum in given range
        IntStream stream = IntStream.range(50, 75);
  
        // storing the maximum value in variable
        // if it is present, else show -1.
        int maximum = stream.max().orElse(-1);
  
        // displaying the maximum value
        System.out.println(maximum);
    }
}

输出:

例3 :

// Java code for IntStream max()
// to get the maximum value in range
// excluding the last element
import java.util.*;
import java.util.stream.IntStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
  
        // To find maximum in given range
        IntStream stream = IntStream.range(50, 50);
  
        // storing the maximum value in variable
        // if it is present, else show -1.
        int maximum = stream.max().orElse(-1);
  
        // displaying the maximum value
        System.out.println(maximum);
    }
}

输出: