Java中的 DoubleStream noneMatch() 示例

DoubleStream noneMatch(DoublePredicate predicate)返回此流的任何元素是否与提供的谓词匹配。如果不需要确定结果，它可能不会评估所有元素的谓词。这是一个短路端子操作。如果一个终端操作在有无限输入时可能会在有限时间内终止，那么它就是短路的。
句法 ：

boolean noneMatch(DoublePredicate predicate)

Where, DoublePredicate represents a predicate 
(boolean-valued function) of one double-valued argument.

返回值：如果流的所有元素都与提供的谓词匹配或流为空，则该函数返回 true，否则返回 false。

注意：如果流为空，则返回 true 并且不评估谓词。

示例 1： noneMatch()函数检查 DoubleStream 的任何元素是否可被 5 整除。

// Java code for DoubleStream noneMatch
// (DoublePredicate predicate) to check whether
// no element of this stream match
// the provided predicate.
import java.util.*;
import java.util.stream.DoubleStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
        // Creating an DoubleStream
        DoubleStream stream =
              DoubleStream.of(3.2, 5.0, 9.3, 12.4, 14.7);
  
        // Check if no element of stream
        // is divisible by 5 using
        // DoubleStream noneMatch(DoublePredicate predicate)
        boolean answer =
             stream.noneMatch(num -> num % 5 == 0);
  
        // Displaying the result
        System.out.println(answer);
    }
}

输出：

false

例2： noneMatch()函数检查两个DoubleStream拼接后得到的DoubleStream中是否没有元素小于2。

// Java code for DoubleStream noneMatch
// (DoublePredicate predicate) to check whether
// no element of this stream match
// the provided predicate.
import java.util.*;
import java.util.stream.DoubleStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
        // Creating an DoubleStream after
        // concatenating two DoubleStreams
        DoubleStream stream = DoubleStream.concat(
            DoubleStream.of(3.3, 4.2, 5.1, 6.6),
            DoubleStream.of(7.2, 8.3, 9.1, 10.5));
  
        // Check if no element of stream
        // is less than 2 using
        // DoubleStream noneMatch(DoublePredicate predicate)
        boolean answer = stream.noneMatch(num -> num < 2);
  
        // Displaying the result
        System.out.println(answer);
    }
}

输出：

true

示例 3： noneMatch()函数显示流是否为空，则返回 true。

// Java code for DoubleStream noneMatch
// (DoublePredicate predicate) to check whether
// no element of this stream match
// the provided predicate.
import java.util.*;
import java.util.stream.DoubleStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
        // Creating an empty DoubleStream
        DoubleStream stream = DoubleStream.empty();
  
        // Using DoubleStream noneMatch() on empty stream
        boolean answer = stream.noneMatch(num -> true);
  
        // Displaying the result
        System.out.println(answer);
    }
}

输出：

true