Question

Could someone take the time to explain me the language underpinnings here :

int foo = myObject.SomeList.Count; for (int i = 0 ; i < foo ; i++) {   myObject.SomeList.Add(bar); } 

goes into an infinite loop because foo references a value that keeps being incremented. Modifying the first line to:

int foo = (int)myObject.SomeList.Count; 

makes it go away, somehow changing foo from reference to value once and for all. This is probably textbook but, why is this happening ?

Many thanks

EDIT : Ok, as Patrick mentions, the infinite loop only happens when there is no prior storage to foo, the cast being pointless, which makes sense. That’s indeed what I thought initially while debugging this. Hence my surprise when the cast fixed it. What actually happened is that I was misled by Visual Studio into thinking I had fixed it when there was actually a problem of synchronization between edited code and executed code, which led to wrong conclusions.

Answer 1

I tried this on my system and can’t replicate your problem. I could however replicate it with the following code, maybe this is what you meant:

// SomeList is not empty before the loop for (int i = 0; i < myObject.SomeList.Count; i++) {     myObject.SomeList.Add(bar); } 

In this case we are not storing the Count in an int, so every time we add to the list, we are comparing i+1 with Count+1, hence the endless loop.