java - Preference when setting and adding an item at the some position in an arraylist -

i guess i'm asking difference between order of these 2 operations on arraylist.

suppose have following arraylists

arraylist<string> list = new arraylist<string>(); arraylist<string> list2 = new arraylist<string>();  list.add("tom"); list.add("jerry"); list.add(1,"harry"); list.set(1,"klaus"); system.out.println(list); 

output

[tom, klaus, jerry] 

then same thing list2except switch last 2 statements

list2.add("tom"); list2.add("jerry"); list2.set(1,"harry"); list2.add(1,"klaus"); system.out.println(list2); 

output

[tom, klaus, harry] 

when value setat posiotionwhy list addan item @ position+1 when attempt add new item @ positionas in second list. shouldn't list2 be?

[tom, klaus] 

and shouldn't listhave

[tom, klaus] 

its simple

add inserts new value @ given index

and

set replace value @ given index.

---

have @ output after each statement.

list.add("tom");      // tom list.add("jerry");    // tom, jerry list.add(1,"harry");  // tom, harry, jerry list.set(1,"klaus");  // tom, klaus, jerry   list2.add("tom");      // tom list2.add("jerry");    // tom, jerry list2.set(1,"harry");  // tom, harry list2.add(1,"klaus");  // tom, klaus, harry 

i hope, got now.