### 5.1 Functions defined on the command-line

Functions can be defined by entering code on the command line, a feature not supported by Matlab. For example, you may type:

         octave:1> function s = hello_string (to_who)
         > ## Say hello
         > if nargin<1, to_who = "World"; end
         > s = ["Hello ",\
         >      to_who];
         > endfunction
         octave:2> hello_string ("Moon")
         ans = Hello Moon