Java vs. C#

Parameter Array

Java
 
Java 5 adds such feature. Below Java 5, you may work around like followings.

public class Test
{
    public static void main (String[] args) {
        System.out.println(add (new int[] {1,2,3,4}));
    }

    public static int add (int[] array) {
       int sum = 0;
       for(int i = 0; i < array.length; i++)
           sum += array[i];
       return sum;
    }
}

prints: 10


class Test 
{
    static void F(int[] args) {
        System.out.println("# of arguments: " + args.length);
        for (int i = 0; i < args.length; i++)
            System.out.println("args[" + i + "] = " + args[i]);
    }
    public static void main(String[] args) {
        F();       //error
        F(1);      //error
        F(1, 2);   //error
        F(1, 2, 3);//error
        F(new int[] {1, 2, 3, 4});
    }
}


class Test
{
    static void F(Object[] args) {
        for(int i = 0; i < args.length; i++) {
            Object o = args[i];
            System.out.println(o.getClass().getName());
        }
        
    }
    public static void main(String[] args) {
        Object[] a = {new Integer(1), "Hello", new Double(123.456)};
        Object o = a;
        F(a);
        //F((Object)a);//error
        //F(o);//error
        F((Object[])o);
    }
}
prints:
java.lang.Integer
java.lang.String
java.lang.Double
java.lang.Integer
java.lang.String
java.lang.Double



In Java 5:

public void aMethod(String... args) {
    for(String s : args) {
        System.out.println(s);
    }
}

The aMethod can be called in the following ways:

aMethod("here","we","go"); //3 argument list
aMethod("to","be","or","not","to","be"); //6 argument list

Note that the compiler will translate the aMethod automatically as:

aMethod(new String[] {"here","we","go"});
aMethod(new String[] {"to","be","or","not","to","be"});

C#
 
The params modifier may be added to the last parameter 
of a method so that the method accepts any number of 
parameters of a particular type
public class Test
{
    public static void Main () {
        Console.WriteLine (add (1, 2, 3, 4).ToString());
    }

    public static int add (params int[] array) {
       int sum = 0;
       foreach (int i in array)
           sum += i;
       return sum;
    }
}
prints: 10


class Test 
{
    static void F(params int[] args) {
        Console.WriteLine("# of arguments: {0}", args.Length);
        for (int i = 0; i < args.Length; i++)
            Console.WriteLine("\targs[{0}] = {1}", i, args[i]);
    }
    static void Main() {
        F();
        F(1);
        F(1, 2);
        F(1, 2, 3);
        F(new int[] {1, 2, 3, 4});
    }
}


using System;
class Test
{
    static void F(params object[] args) {
        foreach (object o in a) {
            Console.Write(o.GetType().FullName);
            Console.Write(" ");
        }
        Console.WriteLine();
    }
    static void Main() {
        object[] a = {1, "Hello", 123.456};
        object o = a;
        F(a);
        F((object)a);
        F(o);
        F((object[])o);
    }
}
prints:
System.Int32 System.String System.Double
System.Object[]
System.Object[]
System.Int32 System.String System.Double