Java DoubleStream mapToInt()用法及代碼示例

DoubleStream mapToInt()返回一個IntStream，其中包括將給定函數應用於此流的元素的結果。

注意：DoubleStream mapToInt()是中間操作。這些操作總是很懶。在Stream實例上調用中間操作，並在完成處理後將中間實例作為輸出提供。
用法:

IntStream mapToInt(DoubleToIntFunction mapper)

參數：

IntStream : 原始整數值元素的序列。這是Stream的int原語專業化。
mapper : 適用於每個元素的無狀態函數。

返回值：該函數返回一個IntStream，其中包括將給定函數應用於此流的元素的結果。

示例1:

// Java code for IntStream mapToInt 
// (DoubleToIntFunction mapper) 
import java.util.*; 
import java.util.stream.IntStream; 
import java.util.stream.DoubleStream; 
  
class GFG { 
  
    // Driver code 
    public static void main(String[] args) 
    { 
        // Creating a DoubleStream 
        DoubleStream stream = DoubleStream.of(2.3, 4.5, 6.4, 
                                              8.7, 10.4); 
  
        // Using IntStream mapToInt(DoubleToIntFunction mapper) 
        // to return an IntStream consisting of the 
        // results of applying the given function to 
        // the elements of this stream. 
        IntStream stream1 = stream.mapToInt(num -> (int)num); 
  
        // Displaying the elements in stream1 
        stream1.forEach(System.out::println); 
    } 
}

輸出：

示例2:

// Java code for IntStream mapToInt 
// (DoubleToIntFunction mapper) 
import java.util.*; 
import java.util.stream.IntStream; 
import java.util.stream.DoubleStream; 
  
class GFG { 
  
    // Driver code 
    public static void main(String[] args) 
    { 
        // Creating a DoubleStream 
        DoubleStream stream = DoubleStream.of(2.3, 4.5, 6.4, 
                                              8.7, 10.4); 
  
        // Using IntStream mapToInt(DoubleToIntFunction mapper) 
        // to return an IntStream consisting of the 
        // results of applying the given function to 
        // the elements of this stream. 
        IntStream stream1 = stream.mapToInt(num -> (int)num - 10000); 
  
        // Displaying the elements in stream1 
        stream1.forEach(System.out::println); 
    } 
}

輸出：

示例3:

// Java code for IntStream mapToInt 
// (DoubleToIntFunction mapper) 
import java.util.*; 
import java.util.stream.IntStream; 
import java.util.stream.DoubleStream; 
  
class GFG { 
  
    // Driver code 
    public static void main(String[] args) 
    { 
        // Creating a DoubleStream 
        DoubleStream stream = DoubleStream.of(1.3, 2.4, 3.4, 
                                              4.5, 5.7); 
  
        // Using IntStream mapToInt(DoubleToIntFunction mapper) 
        // to return an IntStream consisting of the 
        // results of applying the given function to 
        // the elements of this stream. 
        IntStream stream1 = stream.mapToInt(num -> (int)(num * num * num)); 
  
        // Displaying the elements in stream1 
        stream1.forEach(System.out::println); 
    } 
}

輸出：

相關用法

注：本文由純淨天空篩選整理自Sahil_Bansall大神的英文原創作品 DoubleStream mapToInt() in Java。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。