Java variable number or arguments for a method

Question

Is it possible to declare a method that will allow a variable number of parameters    What is the symbolism used in the definition that indicate that the method should allow a variable number of parameters   Answer  varargs

User · Answer

Yes  it s possible   public void myMethod int    numbers       your code

User · Answer

Yup   since Java 5  http   java sun com j2se 1 5 0 docs guide language varargs html

User · Answer

Variable number of arguments   It is possible to pass a variable number of arguments to a method  However  there  are some restrictions    The variable number of parameters must all be the same type They are treated as an array within the method They must be the last parameter of the method   To understand these restrictions  consider the method  in the following code snippet  used to return the largest integer in a list of integers   private static int largest int    numbers         int currentLargest   numbers 0        for  int number   numbers            if  number  gt  currentLargest                currentLargest   number                        return currentLargest      source Oracle Certified Associate Java SE 7 Programmer Study Guide 2012

User · Answer

Yes Java allows vargs in method parameter     public class    Varargs      public  int  add int     numbers               int  result    1          for int  number  numbers                   result  result number                 return  result

User · Answer

That s correct  You can find more about it in the Oracle guide on varargs   Here s an example   void foo String    args        for  String arg   args            System out println arg             which can be called as  foo  foo       Single arg  foo  foo    bar       Multiple args  foo  foo    bar    lol       Don t matter how many  foo new String      foo    bar         Arrays are also accepted  foo       And even no args

User · Answer

For different types of arguments  there is 3-dots    public void foo Object    x        String myVar1    x length  gt  0    String x 0      Hello       int myVar2       x length  gt  1   Integer parseInt  String  x 1     888       Then call it  foo  Hii     foo  Hii   146      for security  use like this       if    x 0  instanceof String     throw new IllegalArgumentException               The main drawback of this approach is that if optional parameters are of different types you lose static type checking     Please  see more variations

[java] Java variable number or arguments for a method

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