C# to Java or What is it worth to learn a new language, knowing the old one?

Question

Java

Hello. I have already mapped out my path to programming. Installed the scope in C#. Recently, for the sake of interest, I looked through vacancies for the query "C#". In the selection, vacancies for the Lead Programmer flashed several times. Almost always in these vacancies there were requirements to know not only C #, but also C ++, and just C, and even Java.
For myself, I regarded it this way - probably if you know one language perfectly, then another (something similar) will be easier to learn? Then how long would it take for an experienced C# programmer to learn Java?

Answer 1

The requirement is absolutely fair, because. knowing one single language, it is simply impossible to become a good (especially suitable for a leading position) programmer. As an absolute minimum, you need to know:
- assembler and processor design,
- at least one "adult" language (C / C ++ / Pascal)
- at least one VM-oriented language (C # / Java)
Knowing C#, learning Java syntax is a matter of one or two days, but learning how to write programs in it correctly is at least one or two serious projects, i.e. a year or two. However, do not be discouraged - after the third language, "learning" the next ones is practically not annoying. And then there comes a state when there are no "new" languages ​​left - there are only languages ​​that you have not used yet ... but if necessary - you just take it and use it, "learning" them, practically, along the way. That's it and there is a sign of suitability for the position of the lead programmer.

Answer 2

See on request ".Net"

Answer 3

For myself, I regarded it this way - probably if you know one language perfectly, then another (something similar) will be easier to learn?

Java and Managed C# are twin brothers. C# is called a clone of Java. The difference between the languages ​​themselves (if we exclude the framework) is not big. Although Java is somewhat left over from C# now.
C++ has direct memory access through pointers (C# also has it, but not Managed). It takes a long time to get used to working with pointers, it is very easy to make mistakes. Otherwise, it is not much different from C#/Java.