Can I declare an array in a if statement?

class Solution {
    public int[] twoSum(int[] nums, int target) {

      for (int i=0; i<= nums.length()-1;i++){

          for (int j =i+1 ; j <= nums.length()-2; j++){

              if((nums[i]+nums[j]) == target )
                  int [] r = {i , j};
                  return r;
          }
      }

    }
}

...

I wrote the following code but I am getting an error in my if statement. I am trying to solve a problem on leetcode but I am running into an error:

Line 9: error: variable declaration not allowed here int [] r = {i , j}; ^

What can I do to fix it and why am I running into this error?