Java LinkedList element()方法及示例

java.util.LinkedList 类的 element() 方法检索，但不删除该列表的头部（第一个元素）。

语法

public E element()

返回值： 该方法返回该列表的头部。

下面是说明 element() 方法的例子

例1 :

// Java program to demonstrate
// element() method
// for Integer value
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        try {
  
            // creating object of LinkedList<Integer>
            LinkedList<Integer> list = new LinkedList<Integer>();
  
            // add some elements to list
            list.add(10);
            list.add(20);
            list.add(30);
  
            // print the linked list
            System.out.println("LinkedList : " + list);
  
            // getting the head of list
            // using element() method
            int value = list.element();
  
            // print the head of list
            System.out.println("Head of list : " + value);
        }
  
        catch (NullPointerException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出:

LinkedList : [10, 20, 30]
Head of list : 10

例2 :

// Java program to demonstrate
// element() method
// for String value
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        try {
  
            // creating object of LinkedList<String>
            LinkedList<String> list = new LinkedList<String>();
  
            // add some elements to list
            list.add("A");
            list.add("B");
            list.add("C");
  
            // print the linked list
            System.out.println("LinkedList : " + list);
  
            // getting the head of list
            // using element() method
            String value = list.element();
  
            // print the head of list
            System.out.println("Head of list : " + value);
        }
  
        catch (NullPointerException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出: