Background: I've been writing code for about 25 years, and I consider myself to be pretty good at what I do.
Depending on the language, I'd say a couple of weeks of full-time work. I tend to dabble with new languages, so the calendar time is on the order of months. That said, I've started a few jobs where I had to learn a new language trial-by-fire style, and I was productive and able to contribute to projects actively within days/weeks.
The thing is that _most_ programming is similar, regardless of language. You still have arrays and tries and dicts and functions. The patterns are largely the same. There are, of course, different families of languages where some patterns are more similar than in other languages, but for the most part, when I pick up a new language, I'm really learning more about syntax and structure than anything else.
For example, Go took me about 2 weeks to become really productive in it. Elixir, on the other hand, has taken me a lot longer (partially because I dislike Ruby -- especially Rails -- and therefore the syntax is fairly alien to me).
Depending on the language, I'd say a couple of weeks of full-time work. I tend to dabble with new languages, so the calendar time is on the order of months. That said, I've started a few jobs where I had to learn a new language trial-by-fire style, and I was productive and able to contribute to projects actively within days/weeks.
The thing is that _most_ programming is similar, regardless of language. You still have arrays and tries and dicts and functions. The patterns are largely the same. There are, of course, different families of languages where some patterns are more similar than in other languages, but for the most part, when I pick up a new language, I'm really learning more about syntax and structure than anything else.
For example, Go took me about 2 weeks to become really productive in it. Elixir, on the other hand, has taken me a lot longer (partially because I dislike Ruby -- especially Rails -- and therefore the syntax is fairly alien to me).
Hope that helped.