How do I call/use the Vim built-in functions?

You can use the “:call” command to invoke a Vim built-in function:

    :call cursor(10,20)

You can use the “:echo” command to echo the value returned by a function:

    :echo char2nr('a')

You can use the “:let” command to assign the value returned by a function to a variable:

    :let a = getline('.')

To store the return value from a function into a Vim register, you can use the following command:

    :let @a = system('ls')

The above command will store the output of the ‘ls’ command into the register ‘a’.