How many programming language should know for best software engineer? ?

Answer 1

In my opinion its more important to know one language on an advanced level instead of knowing 5 languages on a beginner level.

For sure if you know 5 languages on an advanced level its better, but if you know you want to be active in web development its more or less not that sinfull to be a c++ pro.

I think a good start is to find one language you really like and get good skills in this language and then learn basics of other languages.

praxis is more important than only theoretical knowledge

Answer 2

The more you know, the better and easier it will be for you to find software dev. jobs.