Ruby method name with Arithmetic Operators: + - * \ and =, like +=

Question

I have an ADT (Abstract Data Type) and for that I wrote a method +(other). +(other) returns a new ADT.

If I use it like:

adt += otherAdt

It will be overwrite adt.

But now I want to write a method with name +=(other) to change adt instead of create a new one.

I try to name my method +=(other) and get an error.

My alternative is to name it plus=(other).

I know that if I have two arrays aArr and bArr and write:

aArr += bArr

That aArr is a new array with the elements of aArr and bArr and thus has a new Object-ID.

So, is there a way to overwrite +=, -=, *= and *= in Ruby? And if so, how would it look like?

Edit: I asked a question below @Mladen Jablanović's answer.

score 0 · Answer 1 · answered Jun 28 '17 at 21:42

0

You can not. a += b is a shorthand for a = a + b and it always assigns back to a, and you can't redefine assignment, because it is not a method.

answered Jun 28 '17 at 21:42

Mladen Jablanović

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Does this mean `+` is always a method in ruby whereas `=` is either a part of a method name or a standalone for assignment? – Interested Person Jun 28 '17 at 22:07
Yes. `=` is part of a method name if left-hand side is something like `object.method`. Otherwise it's simply an assignment. – Mladen Jablanović Jun 29 '17 at 14:59

Ruby method name with Arithmetic Operators: + - * \ and =, like +=

1 Answers1