aspnet explode and implode like php functions

In php, Explode function converts string into array. Explode breaks the string where it find given delimiter and broken string parts are returned as an array.

public static string [] Explode(string Delimiters,string InputString)
    {
        char [] DelimitersChars = Delimiters.ToCharArray();
        string[] Output = InputString.Split(DelimitersChars);
        return Output;
    }

Example:
string str="one,two,three,four";
string [] Result=Explode(",",str);

Implode function converts array into string.Implode converts array into string.
   public static string Implode(string Glue, string [] Parts)
    {   string Output="";
        if(Parts.Length>0)
            Output+=Parts[0];
        if(Parts.Length>1)
        {
            for(int i=1;i<Parts.Length;i++)
                Output +=Glue+Parts[i];
         }
        return Output;
    }


Example:
string [] str=new string[3];
str[0]="one";
str[1]="two";
str[2]="three";
string x=Implode(",", str);