Computing: How to say "optional parameters"


In programming, a function can have [optional
parameters](http://en.wikipedia.org/wiki/Parameter_%28computer_programming%29#Default_arguments),
for instance getTemperature() could have an optional parameter "Unit" to say I
want the temperature in Kelvin for instance. By default, when specifying no
parameter, it would be in Celsius.

How to say `optional parameters` in Japanese?

ALC says `オプションのパラメータ`:

> Both required and optional parameters are listed.  
>  必須なパラメータおよびオプションのパラメータを列挙します。

But I believe they are wrong, and their translation has a different meaning.




You are looking for

> 必須（の/な）引数 => required parameter(s).

and

> 任意（の/な）引数 => optional parameter(s)




You are looking for

> 必須（の/な）引数 => required parameter(s).

and

> 任意（の/な）引数 => optional parameter(s)

