What does the syntax f.(10) mean?

In irb I have defined the lambda

f=lambda { |x| x+1 }

and then issued (because I have seen it in someone else code)


which computed 11. But what does the f.(10) syntax mean? It computes the
same as f(10), but why?

f.(10) is an alias for f.call(10) - see documentation for Proc#call

f(10) won’t work, you’ve probably meant f[10] as an equivalent method

Thank you!