要在链表中的第一个项目之前添加一个项目，我们使用LinkedList.addFisrt()方法，并在链表中的最后一个项目之后添加一个项目，我们使用LinkedList.addLast()方法。
package org.nhooo.example.util;
import java.util.LinkedList;
public class LinkedListAddItems {
public static void main(String[] args) {
LinkedList<String> grades = new LinkedList<>();
grades.add("B");
grades.add("C");
grades.add("D");
grades.add("E");
System.out.println("Original values are:");
System.out.println("====================");
for (String grade : grades) {
System.out.println("Grade = " + grade);
}
grades.addFirst("A");
grades.addLast("F");
System.out.println("New values are:");
System.out.println("====================");
for (String grade : grades) {
System.out.println("Grade = " + grade);
}
}
}该程序的结果如下：
Original values are: ==================== Grade = B Grade = C Grade = D Grade = E New values are: ==================== Grade = A Grade = B Grade = C Grade = D Grade = E Grade = F