Why output is printed in asci code instead of integer ?dart

Question

I don't know why output is printed in ascii code instead of integer value ,what wrong with my code ?

import 'dart:io';

void main() {
  int n = 0;
  print("input: ");

  do {
    n = stdin.readByteSync();
  } while (n>1000 || n<0);

  if (n % 4 == 0) {
    print("output: ");
    print(n);
    n++;
  } else {
    print("output: ");
    n--;
    print(n);
  }
}

Answer 1

Paste your code so it can be easier to help you. I could have given you a fixed source code if you would have provided.

Instead, I'll try to explain: Your stdin will be provided as a string, you read it as bytes so 5 will be come 35 as hex. When you print it, my guess is that it will automatically be converted to a decimal value (53, and the output shows 52 because 53 % 4 = 1 and then to decrease with n-- before printing it so it become 52 ) . Those numbers like you said of the ASCII Table . In order to fix it, make sure you have the string representation of the input (stdin). Then convert the value to integer: "2".toInt()

Edit: I could have easily find the complete solution, You need to get the stdin as a string first: readLineSync and convert it to int:

n = int.parse(stdin.readLineSync());

Note: Code not tested, but it's pretty straight forward.

Answer 2

Get the value as String using stdin.readLineSync() then parse it to int like below:

import 'dart:io';

void main() {
  int n = 0;
  print("input: ");

  do {
    n = int.parse(stdin.readLineSync());
  } while (n>1000 || n<0);

  if (n % 4 == 0) {
    print("output: ");
    print(n);
    n++;
  } else {
    print("output: ");
    n--;
    print(n);
  }
}