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Is there a limit of elements that could be stored in a List ? or you can just keeping adding elements untill you are out of memory ?

Hannoun Yassir
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1 Answers1

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The current implementation of List<T> uses Int32 everywhere - to construct its backing array, for its Count property, as an indexer and for all its internal operations - so there's a current theoretical maximum of Int32.MaxValue items (2^31-1 or 2147483647).

But the .NET framework also has a maximum object size limit of 2GB, so you'll only get anywhere near the items limit with lists of single-byte items such as List<byte> or List<bool>.

In practice you'll probably run out of contiguous memory before you hit either of those limits.

LukeH
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    *Theoretically* that means you can only randomly access items up to `Int32.MaxValue`, not how many elements can there be, *theoretically*, of course. – R. Martinho Fernandes Nov 13 '09 at 17:46
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    @Martinho: Well, the current implementation uses `Int32` *everywhere*, so it's not just random access that's restricted to 2^31 items. (Of course, the use of `Int32` internally is just an implementation detail, but properties like the indexer and `Count` are part of the public contract.) – LukeH Nov 13 '09 at 18:22