Why can't strings be mutable in Java and .NET?

Question

Why is it that they decided to make String immutable in Java and .NET (and some other languages)? Why didn\'t they make it mutable?

Answer 1

Immutability is not so closely tied to security. For that, at least in .NET, you get the SecureString class.

Later edit: In Java you will find GuardedString, a similar implementation.