Question

I have a nested loop “structure” in my code. Sometimes, I get the below message.

Collection was modified; enumeration operation may not execute.

I have a collection I am looping through, like below. Coll is a List<string>

foreach (string[] s1 in obj.Coll
{
    foreach (string s in s1) { }
}

For each string in the array, I need to work with it (read as read the value, not write).
All I do with it is get directories (this value is a path) and split this string into an array.

How can this be resolved?

Answer 1

You can try:

foreach (string[] s1 in obj.Coll.ToArray())
{

That will take a copy before starting iteration!