Scala List filter() 方法示例

filter()方法用于选择列表中满足指定谓词的所有元素。

Method Definition: def filter(p: (A) => Boolean): List[A]

Return Type: It returns a new list consisting all the elements of the list which satisfies the given predicate.

示例 #1：

// Scala program of filter()
// method
  
// Creating object
object GfG
{ 
  
    // Main method
    def main(args:Array[String])
    {
      
        // Creating a list
        val m1 = List(5, 12, 3, 13)
          
        // Applying filter method
        val result = m1.filter(_ < 10)
          
        // Displays output
        println(result)
      
    }
}

输出：

List(5, 3)

示例 #2：

// Scala program of filter()
// method
  
// Creating object
object GfG
{ 
  
    // Main method
    def main(args:Array[String])
    {
      
        // Creating a list
        val m1 = List(5, 12, 3, 13)
          
        // Applying filter method
        val result = m1.filter(_ < 3)
          
        // Displays output
        println(result)
      
    }
}

输出：

List()

在这里，由于没有元素满足所述谓词，因此返回一个空列表。