Does FirstOrDefault return a reference to the item in the collection or the value?

Question

Does FirstOrDefault return a reference to the item in the collection or the value of the item?

var obj = myCollection.FirstOrDefault(x => x.Param == "match condition");  
if (obj != null)
{
    obj  = newObjectOfCollectionType; //if found, replace with the changed record
}

Will this code replace the object reference in the myCollection with the new object, or will it do nothing to myCollection?

Answer 1

var obj = myCollection.FirstOrDefault(x => x.Param == "match condition");  
if (obj != null)
{
    obj  = newObjectOfCollectionType; --> this will not reflect in the collection
}

var obj = myCollection.FirstOrDefault(x => x.Param == "match condition");  
if (obj != null)
{
    obj.Property = newValue; --> this will reflect in your object in the original collection
}

Answer 2

It does nothing to the collection. You can change the collection like this:

int index = myCollection.FindIndex(x => x.Param == "match condition");  
if (index != -1)
{
    myCollection[index]  = newObjectOfCollectionType;
}