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Editorial Team
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Asked: 2026-06-02T05:48:55+00:00

I’ve got a Java program which stores a list of cricket club players using

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I’ve got a Java program which stores a list of cricket club players using an arraylist.
In the club class I have a static field which keeps track of of how many players are registered in the club. Also I assign a player ID to the static field so that each time a player is added he gets an ID. This is how

id = regPlayer++;

regPlayer is the static field, which is initialized as 1

The problem I’m having is that if I want to remove a player from the arraylist I can’t seem to be able to update the IDs.
For example if I have four players they will have the following IDs before I remove any of them:

Player 1 ID = 1
Player 2 ID = 2
Player 3 ID = 3
Player 4 ID = 4

If I remove Player 2 I now want the third player to have ID 2 and the fourth player to have ID 3, like that:

Player 1 = 1
Player 3 = 2
Player 4 = 3

Is there a way of achieving this with arraylists and how?

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1 Answer

  1. Editorial Team

    IDs should generally be immutable. You should not be shifting IDs, simply because you want to make the ID double as an index into the list. So don’t update the IDs. That is about the same as trying to update someone’s Social Security Number… bad idea.

    I can only guess that you want the ID to reflect the index position so that you can somehow quickly know which position a given Object occupies. If that’s the case, just use: List.indexOf(Object) to look up the position, rather than counting on the ID to also represent the position.

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