C#13 paramsコレクション

T f(T1 p1, T2 p2, ... , params T3[] p) {}

> string JoinString(string delim , params IEnumerable<string> prm) => string.Join(delim,prm);
> JoinString("," , "Paul","John","George","Ringo")		// 引数の列挙
"Paul,John,George,Ringo"
> JoinString("," , ["Paul","John","George","Ringo"])	// 配列
"Paul,John,George,Ringo"
>List<string> lst = ["Paul","John","George","Ringo"];
> JoinString("," , lst)									// リスト
"Paul,John,George,Ringo"
>JoinString("," , lst.Where(v=>v.Contains("o")))		// クエリ
"John,George,Ringo"