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Search elements of LinkedList Java example

  1. /*
  2.   Search elements of LinkedList Java example
  3.   This java example shows how to search element of Java LinkedList using indexOf
  4.   and lastIndexOf methods.
  5. */
  6.  
  7. import java.util.LinkedList;
  8.  
  9. public class SearchElementLinkedListExample {
  10.  
  11.   public static void main(String[] args) {
  12.  
  13.     //create LinkedList object
  14.     LinkedList lList = new LinkedList();
  15.    
  16.     //add elements to LinkedList
  17.     lList.add("1");
  18.     lList.add("2");
  19.     lList.add("3");
  20.     lList.add("4");
  21.     lList.add("5");
  22.     lList.add("2");
  23.    
  24.     /*
  25.      * To search first occurrence of an element of LinkedList, use
  26.      * int indexOf(Object element) method.
  27.      *
  28.      * This method returns index of first occurrence of element if found in
  29.      * the LinkedList. It returns -1 if element not found.
  30.      */
  31.    
  32.      int index = lList.indexOf("2");
  33.      if(index != -1)
  34.      {
  35.        System.out.println("First occurrence of 2 in LinkedList is at index : "
  36.                                                                      + index);
  37.      }
  38.      else
  39.      {
  40.       System.out.println("LinkedList does not contain 2");
  41.      }
  42.    
  43.     /*
  44.      * To search last occurrence of an element of LinkedList, use
  45.      * int lastIndexOf(Object element) method.
  46.      *
  47.      * This method returns index of last occurrence of element if found in
  48.      * the LinkedList. It returns -1 if element not found.
  49.      */
  50.    
  51.      index = lList.lastIndexOf("2");
  52.      if(index != -1)
  53.      {
  54.       System.out.println("Last occurrence of 2 in LinkedList is at index : "
  55.                                                                      + index);
  56.      }
  57.      else
  58.      {
  59.       System.out.println("LinkedList does not contain 2");
  60.      }
  61.    
  62.   }
  63. }