Create a function that takes 2 integers in form of a string as an input, and outputs the sum (also as a string):
Example: (Input1, Input2 -->Output)
"4", "5" --> "9"
"34", "5" --> "39"
"", "" --> "0"
"2", "" --> "2"
"-5", "3" --> "-2"
Notes:
- If either input is an empty string, consider it as zero.
- Inputs and the expected output will never exceed the signed 32-bit integer limit (
2^31 - 1)
def sum_str(a, b)
(a.to_i + b.to_i).to_s
end