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[.net] Anyone a guru with C# Lists?

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Hi, I have a list and i want to iterate through it and compare each object in the list with every other object in the list. I thought of running 2 foreach loops, the first one selecting an object and the second one comparing it to every other but it ends up comparing itself with itself. Thanks for any info. Cheers

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void Compare(List list){
foreach(Object a in list){
foreach(Object b in list){
if (a!=b){
CompareObject(a,b);
}
}
}
}

void CompareObject(Object a,Object b){
//do stuff here
}


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Alternatively:


void Compare(IList list)
{
for( int i = 0; i < list.Count; ++i )
{
for( int j = i + 1; j < list.Count; ++j )
{
CompareListItem(list, list[j]);
}
}
}

void CompareListItem(object listItem1, object listItem2)
{
// do comparison stuff
}




This will cut out on comparisons against the same object and against objects that have already been compared. Kaze's example will work but there's be two comparisons of a lot of objects:

CompareObject(1, 2);
CompareObject(1, 3);
CompareObject(1, 4);
...
CompareObject(2, 1);
...
CompareObject(3, 1);
...
CompareObject(4, 1);
...
etc

Also, if you're using .NET 2.0 I'd recommend using the Systems.Collections.Generics.List<T> rather than just a standard System.Collections.List.

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