In the following two examples I do the same thing, creating a constant String and using the concat method to modify it. Because it’s a constant, I expect a compiler warning but only receive one in the second example when I use the assignment operator. Why is this?
X = 'hello' X.concat(' world') puts X # no warning X = 'hello' X = X.concat(' world') puts X # warning: already initialized Since the concat method modifies the string in place, that’s normally what I would do, since there’s no need to use an assigment operator. So, why does the presence of the assignment operator cause the compiler to identify these two operations as being different?
This is because you’re re-defining a new X. When you redefine a constant it gives you the ‘already initialized’ error. The first example does not give this error because you’re not redefining X, you’re modifying it.