This is an example of how to search the elements in a LinkedList. Searching the elements in a LinkedList implies that you should:
- Create a new LinkedList.
- Populate the list with elements, with the
add(E e)API method of the LinkedList. - Invoke the
contains(Object o)API method of LinkedList, to check if the list contains the specified object. It returns true if the list contains the object and false otherwise. - Then invoke the
indexOf(Object o)API method of LinkedList, to get the index of the first occurance of the specified element in LinkedList or -1 if the specific element is not found. - To get the index of the last occurance of the specified element in LinkedList use the
lastIndexOf(Object o)operation.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.util.LinkedList;
public class SearchLinkedList {
public static void main(String[] args) {
// Create a LinkedList and populate it with elements
LinkedList linkedList = new LinkedList();
linkedList.add("element_1");
linkedList.add("element_2");
linkedList.add("element_3");
linkedList.add("element_1");
/*
boolean contains(Object element) operation returns true
if the LinkedList contains the specified object, false otherwise.
*/
boolean found = linkedList.contains("element_2");
System.out.println("Found element_2 : " + found);
/*
int indexOf(Object element) operation returns the index of the
first occurance of the specified element in LinkedList or -1 if
the specific element is not found. To get the index of the last
occurance of the specified element in LinkedList use the
int lastIndexOf(Object element) operation instead.
*/
int index = linkedList.indexOf("element_3");
System.out.println("Found element_3 : " + (index == -1?false:true) + ", in position : " + index);
int lastIndex = linkedList.lastIndexOf("element_1");
System.out.println("Found element_1 : " + (lastIndex == -1?false:true) + ", in position : " + lastIndex);
}
}
Output:
Found element_2 : true
Found element_3 : true, in position : 2
Found element_1 : true, in position : 3
This was an example of how to search the elements in a LinkedList in Java.
