Reputation: 65
A bug in a program I'm writing as an assignment for my java. Objective: program should take two parameters and find all the odd numbers between those parameters. Then it should return the sum of all those numbers.
Bug: When the parameters are negative or starting number is greater than the ending number, it should return -1. But my program is returning 0.
Maybe my program isn't updating the sum value inside the loop. But even so, as per return condition, my function should return -1, not the sum.
public class SumOddRange{
public static void main(String[] args){
System.out.println(sumOdd(10,5));
}
public static boolean isOdd(int number){
return (number<0)||(number%2==0)?false:true;
}
public static int sumOdd(int start, int end){
int sum = 0;
for(int i=start; i<=end; i++){
if(isOdd(i)){
sum+=i;
}
}
return (start<=0)&&(start>end)? -1: sum;
}
}
Upvotes: 1
Views: 232
Reputation: 354
There is a logic error in your line return (start<=0)&&(start>end)? -1: sum;
You have to return -1 if start is <0 or start > end, so use "||" (logical Or) instead of "&&" (logical and):
return (start<=0)||(start>end)? -1: sum;
Please go through @luk2302's answer for a better solution.
Upvotes: 1
Reputation: 57114
Put the input check as the first thing in your method and change the &&
to an ||
since you want to return if the first check fails or the second check fails, not only if both fail. And the isOdd
can be inlined:
public static int sumOdd(int start, int end){
if (start <= 0 || start > end)
return -1;
int sum = 0;
for (int i = start; i <= end; i++) {
if (i % 2 != 0) { // or if (i % 2 == 1) {
sum += i;
}
}
return sum;
}
Upvotes: 3