Using LINQ to Update A Property in a List of Entities

Like this:

var result = GetMyIEnumerable()
                .ToList();
result.ForEach(x => x.property1 = 100);

To Darin's point, LINQ is built for querying. I've gotten into the mindset when working with LINQ that objects being queried should be treated as immutable. However, the Select operator is also great for transformations.

So, you could solve your problem by transforming from one set to another as follows:

var result = myEntityCollection.Select(e => {
   var ret = e;
   e.property1 = 100;
   return e; });

The items in the original collection are untouched, but the items in result will now all have property1 set to 100.