Java - 检查`LinkedList`中是否存在特定元素

原文： https://beginnersbook.com/2014/07/java-check-if-a-particular-element-exists-in-linkedlist-example/

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