Object.CompareTo(Object) for unknown data type

Question

I am trying to compare objects in an object[] that are of a single type (unknown at runtime). They are of System.string, int, decimal, Datetime, or bool types.

Is there a way to compare two of these objects to determine if one is greater or less than another without having to cast them into their appropriate type first?

You have at least to cast them to IComparable and then use CompareTo . — user629926, Nov 22 '11 at 20:52

score 7 · Accepted Answer · answered Nov 22 '11 at 20:51

7

The types in question all implement IComparable, so, if being able to compare elements is an intrinsic requirement of your array, you could declare it as an IComparable[] instead.

answered Nov 22 '11 at 20:51

Marcelo Cantos

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Hah, You were 3 seconds faster ;-) – Marcin Deptuła Nov 22 '11 at 20:53

score 2 · Answer 2 · answered Nov 22 '11 at 20:51

2

All of those types implement IComparable interface, so you can cast your objects to IComparable (or just keep an IComparable[] array instead of object[]). Then you can use CompareTo(object x) method.

answered Nov 22 '11 at 20:51

Marcin Deptuła

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score 1 · Answer 3 · answered Nov 22 '11 at 20:51

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All of the types you mention implements IComparable, so you can use IComparable.CompareTo. As an example:

object[] ints = new object[] { 2, 1, 3};
object n = 2;
var compareResults = ints.OfType<IComparable>().Select(c => c.CompareTo(n));

answered Nov 22 '11 at 20:51

driis

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Object.CompareTo(Object) for unknown data type

3 Answers3