Java Guava Sets union()用法及代码示例

Guava 的Sets.union()返回两个集合的不可修改的视图。返回的集合包含任一后备集中包含的所有元素。对返回的set进行迭代，首先对set1的所有元素进行迭代，然后依次对set2的每个元素进行迭代，这些迭代不包含在set1中。

用法:

public static <E> 
  Sets.SetView<E> 
    union(Set<? extends E> set1, 
          Set<? extends E> set2)

返回值：此方法返回两个集合的不可修改的视图。

范例1：

// Java code to show implementation 
// of Guava's Sets.union() method 
  
import com.google.common.collect.Sets; 
import java.util.Set; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
        // Creating first set 
        Set<Integer> 
            set1 = Sets.newHashSet(1, 2, 3, 4, 5); 
  
        // Creating second set 
        Set<Integer> 
            set2 = Sets.newHashSet(3, 5, 7, 9); 
  
        // Using Guava's Sets.union() method 
        Set<Integer> 
            answer = Sets.union(set1, set2); 
  
        // Displaying the union of set set1 and set2 
        System.out.println("Set 1:"
                           + set1); 
        System.out.println("Set 2:"
                           + set2); 
        System.out.println("Set 1 union Set 2:"
                           + answer); 
    } 
}

输出：

Set 1:[1, 2, 3, 4, 5]
Set 2:[9, 3, 5, 7]
Set 1 union Set 2:[1, 2, 3, 4, 5, 9, 7]

范例2：

// Java code to show implementation 
// of Guava's Sets.union() method 
  
import com.google.common.collect.Sets; 
import java.util.Set; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
        // Creating first set 
        Set<String> 
            set1 = Sets.newHashSet("G", "e", "e", "k", "s"); 
  
        // Creating second set 
        Set<String> 
            set2 = Sets.newHashSet("g", "f", "G", "e"); 
  
        // Using Guava's Sets.union() method 
        Set<String> 
            answer = Sets.union(set1, set2); 
  
        // Displaying the union of set set1 and set2 
        System.out.println("Set 1:"
                           + set1); 
        System.out.println("Set 2:"
                           + set2); 
        System.out.println("Set 1 union Set 2:"
                           + answer); 
    } 
}

输出：

Set 1:[k, s, e, G]
Set 2:[e, f, g, G]
Set 1 union Set 2:[k, s, e, G, f, g]

相关用法

注：本文由纯净天空筛选整理自Sahil_Bansall大神的英文原创作品 Sets union() function | Guava | Java。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。