Need the Index No of an Array List, by giving the certain text of the element String

Question

I want to get the particular index of the array list, by using only contained text. Say suppose,

I have arraylist as

Test = {"LabTechnician","SeniorLabTechnician_4","Pathologist","SeniorLabTechnician_6"}

If want the index nos of both the SeniorLabTechnician, i have to use the exact string in the indexOf and lastindexOf method. Like Test.indexOf("SeniorLabTechnician_4") and Test.lastindexOf("SeniorLabTechnician_6")

this is will get me the exact answer.. But instead of that,by using only prefix say like senior or some thing like, i want the exact same answer before..

Like Test.indexOf("Senior") and Test.lastindexOf("Senior")...

Please suggest

Answer 1

private int getsearchPos(String searchvalue) {
  for(String hj : Test)
     {
         if(hj.toLowerCase().startsWith(searchvalue.toLowerCase()))
                      return Test.indexOf(hj);
     }
    return -1;
}

this should help.

Answer 2

Loop over the list and compare the elements with contains:

int indexOfContains(List<String> lst, String what) {
  for(int i=0;i<lst.size();i++){
    //this will make the check case insensitive, see JAVY's comment below:
    //if(lst[i].toLowerCase().contains(what.toLowerCase())) {
    if(lst[i].contains(what)){
      return i;
    }
  }
  return -1;  
}

If you want something like lastIndexOf then just reverse the order in which the list is iterated.

Answer 3

As I understand, you want to modify default behaviour of indexOf and lastIndexOf methods of ArrayList.

1. My solution is create a new class CustomArrayList extends ArrayList.
2. Override indexOf method

3. Override lastIndexOf method

   public class CustomArrayList extends ArrayList {
   
     public int indexOf(Object o) {
       if (o == null) {
           for (int i = 0; i < size(); i++)
               if (get(i) == null)
                   return i;
       } else {
           for (int i = 0; i < size(); i++)
               if(o instanceof String) {
                   if(get(i).toString().startsWith(o.toString())) {
                       return i;
                   }
               } else {
                   if (o.equals(get(i)))
                       return i;
               }
       }
       return -1;
   }
   
   public static void main(String[] args) {
       List list = new CustomArrayList();
       list.add("LabTechnician");
       list.add("SeniorLabTechnician_4");
       list.add("Pathologist");
       list.add("SeniorLabTechnician_6");
       System.out.println(list.indexOf("Senior"));
   }
   

   }

I left overriding of lastindexof method for you.