CODEWITHSUNDEEP
vb.netlistforeach
John
John

Reputation: 16007

Does For Each acting on a List always visit elements in the same order?

Will the elements in myList always be visited in the same order with a For Each loop (assuming I don't alter the list)?

Dim myList As New List(Of MyElement)

....

For Each myElem As MyElement In myList

    ' yadda yadda yadda

Next

Upvotes: 0

Views: 271

Answers (1)

Jon Skeet
Jon Skeet

Reputation: 1500515

Yes, they will always be in the natural list order.

For Each is basically a language constructor around calling GetEnumerator()/MoveNext()/Current, so the ordering is up to the List(Of T) class - which does indeed preserve ordering.

To give a contrasting example, if you iterate over the key/value pairs in a Dictionary(Of TKey, Of TValue) then the order isn't guaranteed and adding or removing one entry is allowed to change the entire ordering.

Upvotes: 6

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