Arbitrary number of arguments | Java

Varargs (short name for variable arguments) is used to pass an arbitrary number of values to a method. You use varargs when you don’t know how many of a particular type of argument will be passed to the method.

To use varargs, follow the type of the last parameter by an ellipsis (three dots, …), then a space, and the parameter name. The method can then be called with any number of that parameter, including none.

class VarargExample {

  public int sumNumber(int ... args){
    System.out.println("argument length: " + args.length);

    int sum = 0;
    for(int x: args){
        sum += x;
    }
    
    return sum;
  }

  public static void main( String[] args ) {

    VarargExample ex = new VarargExample();

    int sum2 = ex.sumNumber(2, 4);
    System.out.println("sum2 = " + sum2);

    int sum4 = ex.sumNumber(1, 3, 5, 7);
    System.out.println("sum4 = " + sum4);
  }
}

The code in the method body will treat the parameter as an array in either case.