default-arguments.md

Defaulting the argument list

Functions of zero, one, two and three arguments:

zero:{a+b}
one:{x+10}
two:{x+y}
three:{x+y%z}

Be consistent in your use of x, y, and z to mean the first, second, and third arguments to a function.

If you don’t use the default pattern provided by q, avoid using these letters as local variables, or as arguments occupying other positions in the argument list. For example:

ugh:{[y;x]
  …

urk:{[a;b]
  x:a+b;
  …