Why strings behave like ValueType

Question

I was perplexed after executing this piece of code, where strings seems to behave as if they are value types. I am wondering whether the assignment operator is operating on

Answer 1

If I remember correctly once Erik Lippert wrote on SO that this behavior was chosen so that multihreading is easier and more secure. This way when you store a string in a1, you know that only you can change it. It cannot be changed from other threads for example.