Usage of printf command in vim

Question

I see from :h printf that there's a print function in vim:

printf({fmt}, {expr1} ...) printf() Return a String with {fmt}, where "%" items are replaced by the formatted form of their respective arguments. Example: printf("%4d: E%d %.30s", lnum, errno, msg)

However, when I try doing something basic like:

:printf('Hello, %s', 'name')

I get the following error:

E492: Not an editor command: printf('Hello, %s', 'name')

What would be the correct usage, if any, of the printf command, and where can it be used?

Answer 1

printf() is a function, not a command. And in Vim everything must start with a command.

So while calling a function either put it on rhs, or use :call command (when you don't care for return value).

But note that printf() is analog to sprintf() in C, so :call printf(...) doesn't make any sense. So you must do

:echo printf('Hello, %s', 'name')