Java method to sum any number of ints

Question

I need to write a java method sumAll() which takes any number of integers and returns their sum.

sumAll(1,2,3) returns 6
sumAll() returns 0
sumAll(20) returns 20

I don't know how to do this.

Answer 1

Use var args

public long sum(int... numbers){
      if(numbers == null){ return 0L;}
      long result = 0L;
      for(int number: numbers){
         result += number;
      }
      return result;   
}