Concatenate characters in Scala

Question

Suppose we have a string "code". How would we concatenate any two characters? Say for example we need to concatenate last two characters,

str.init.last + str.last gives result as 201. How would we get de instead?

That's not concatenating, that's simply dropping the first two chars. Is that all you want to do? — Yuval Itzchakov
– Yuval Itzchakov, Commented Jan 11, 2017 at 6:29
Then specify what exactly you want to do. If you're talking about general string fiddling, you can use indexes into the string. — Yuval Itzchakov
– Yuval Itzchakov, Commented Jan 11, 2017 at 6:36
My question in general was if we can concatenate characters? One possible way as @Michal has shown and as you have suggested is to use indexes and convert the result into a String! Another way, similarly, could be s"${str.init.last}${str.last}". I was wondering if characters can be concatenated without conversion to a String? — Kity Cartman
– Kity Cartman, Commented Jan 11, 2017 at 6:44
It depends on what is your goal. Char is in general a number representing character in ASCII table. Adding two Char values is in fact adding numbers. If you wish to produce String, you cannot use addition. Another way is to call .toString method on each char before addition but it makes code less readable. — Michał
– Michał, Commented Jan 11, 2017 at 6:58

Michał · Accepted Answer · 2017-01-11 06:33:36Z

You can use string interpolation to make any combination of characters:

scala> val code = "code" code: String = code scala> s"${code(1)}${code(3)}" res0: String = oe

hartmut27 · Accepted Answer · 2023-01-31 00:27:05Z

"code".init.last.toString + "code".last.toString val res7: String = de

(use toString first to convert char to String and then concatenate with +)

2 Answers 2