Scala 不可变 TreeSet filter() 方法

在 Scala 的不可变TreeSet class中， filter()方法用于返回一个新的 TreeSet，它由满足给定谓词的所有元素组成。

Method Definition: def filter(pred: (A) => Boolean): TreeSet[A]

Return Type: It returns a new TreeSet that consists of all the elements that satisfy a given predicate.

示例 #1：

// Scala program of filter() 
// method 
  
// Import TreeSet
import scala.collection.immutable._
  
// Creating object 
object GfG 
{ 
  
    // Main method 
    def main(args:Array[String]) 
    { 
      
        // Creating TreeSet
        val t1 = TreeSet(1, 3, 2, 7, 6, 5) 
          
        // Print the TreeSet
        println(t1) 
          
        // Applying filter() method  
        val result = t1.filter(x => {x % 2 == 1})
          
        // Displays output 
        println("Odd Elements: " + result)
          
    } 
} 

输出：

TreeSet(1, 2, 3, 5, 6, 7)
Odd Elements: TreeSet(1, 3, 5, 7)

示例 #2：

// Scala program of filter() 
// method 
  
// Import TreeSet
import scala.collection.immutable._
  
// Creating object 
object GfG 
{ 
  
    // Main method 
    def main(args:Array[String]) 
    { 
      
        // Creating TreeSet
        val t1 = TreeSet(1, 3, 2, 7, 6, 5) 
          
        // Print the TreeSet
        println(t1) 
          
        // Applying filter() method  
        val result = t1.filter(x => {x % 2 == 0})
          
        // Displays output 
        println("Even Elements: " + result)
          
    } 
} 

输出：

TreeSet(1, 2, 3, 5, 6, 7)
Even Elements: TreeSet(2, 6)