Java 集合 检查LinkedList中是否存在特定元素

在这个例子中，我们将看到如何使用contains()方法检查LinkedList中是否存在特定元素：

public boolean contains(Object o)：如果此列表包含指定的元素，则返回true。更正式地，当且仅当此列表包含至少一个元素e时才返回true（o == null? e == null: o.equals(e)）。

import java.util.LinkedList;

public class CheckLinkedList {
 public static void main(String[] args) {

    // Creating LinkedList of String Elements
    LinkedList<String> linkedlist = new LinkedList<String>();

    // Populating it with String values
    linkedlist.add("AA");
    linkedlist.add("BB");
    linkedlist.add("CC");
    linkedlist.add("DD");
    linkedlist.add("EE");

    // contains() method checks whether the element exists
    if (linkedlist.contains("CC")) {
       System.out.println("Element CC is present in List");
    } else {
       System.out.println("List doesn't have element CC");
     }

    //Checking for element FF
    if (linkedlist.contains("FF")) {
       System.out.println("Element FF is present in List");
    } else {
        System.out.println("List doesn't have element FF");
      }
 }
}

输出：

Element CC is present in List
List doesn't have element FF