Scala Stack head() 方法与示例

在 Scala Stack class中， head()方法用于返回堆栈的顶部元素。

Method Definition: def head: A

Return Type: It returns the top element of the stack.

示例 #1：

// Scala program of head() 
// method 
  
// Import Stack 
import scala.collection.mutable._
  
// Creating object 
object GfG 
{ 
  
    // Main method 
    def main(args:Array[String]) 
    { 
      
        // Creating stack
        val s1 = Stack(1, 3, 2, 7, 6, 5) 
          
        // Print the stack 
        println(s1) 
           
        // Applying head method  
        val result = s1.head 
          
        // Display output 
        print("Top element of the stack: " + result) 
         
    } 
} 

输出：

Stack(1, 3, 2, 7, 6, 5)
Top element of the stack: 1

示例 #2：

// Scala program of head() 
// method 
  
// Import Stack 
import scala.collection.mutable._
  
// Creating object 
object GfG 
{ 
  
    // Main method 
    def main(args:Array[String]) 
    { 
      
        // Creating stack
        val s1 = Stack(5, 3, 2, 7, 6, 1) 
          
        // Print the stack 
        println(s1) 
           
        // Applying head method  
        val result = s1.head 
          
        // Display output 
        print("Top element of the stack: " + result) 
         
    } 
} 

输出：

Stack(5, 3, 2, 7, 6, 1)
Top element of the stack: 5