[dmytro__p]

I was curious what Julia decided to use for string concatenation (+ method would be the least surprising option for me since it's common for the most of source code in use, even while the string concatenation is non commutative).

I was surprised to find Julia uses the multiplication method for string concatenation. For me it feels as wrong as using bitshift operators for I/O but maybe I'm missing something.

[enriquto]

+ is terribly wrong for string concatenation and people who used it first were illiterate freaks. If I had to chose among my many reasons to avoid python this by far is the strongest one. I'm forced to use formatting operators and string interpolation just to avoid the stupid +

Multiplication for concatenation makes perfect sense: it is commutative, associative, and consistent with mathematical notation. A space would be even better. And the empty string would be great, but maybe difficult to implement if you want to allow multiple-letter variable names, as julia seems to do.

[StefanKarpinski]

We considered juxtaposition with string literals for concatenation for a while, as in `file ".txt"`. That would make `a "" b` a natural string concatenation syntax, which rather like it, but Jeff felt it was a bit too clever/weird, so we didn't do it.

[cbkeller]

Oh interesting. That would work too, but `*` is really quite nice in the context that string concatenation is properly the associative binary operation of a free monoid.

[dmytro__p]

Interesting, is multiplication method used for arrays concatenation as well?

Even if using multiplication to join strings may be consistent with some properties of mathematical notation, it's less consistent with the usual meaning of the words (I checked the cosine similarity using GloVe 6B words embeddings, the similarity between "add" and "join" is 0.4 while between "multiply" and "join" is only 0.03), so it's probably the balance between being the general purpose and math oriented language.