# arguments (proc)

Source: https://ref.dm-lang.org/proc/arguments/

The parameters to a proc are referred to as arguments. To define argument variables, place them inside the ()'s in the proc definition. A default value may be specified. Otherwise, arguments default to null.

```dm
proc/Sum(a,b)
  return a + b
```

```dm
proc/set_mob_desc(mob/M,desc="big and bad")
  M.desc = desc
  world << "The new desc for [M] is [desc]."
```

Note how the variable type may be specified. It is just like any other variable definition, except "`var/`" is implicit and does not need to be typed.

### See also
- [named arguments (proc)](https://ref.dm-lang.org/proc/arguments/named.md)
- [path operators](https://ref.dm-lang.org/operator/path/index.md)
- [arglist proc](https://ref.dm-lang.org/proc/arglist.md)
- [args var (proc)](https://ref.dm-lang.org/proc/var/args.md)

## Pages

- [named arguments (proc)](https://ref.dm-lang.org/proc/arguments/named.md)