Problem realted to condition and loop and pattern

1.Question
=> Find n is +ve,-ve or 0?
code:-

import 'dart:io';

void main() {
  print('Om Namah Shivay');
  int n = int.parse(stdin.readLineSync()!);
  if (n > 0) {
    print('$n is positive');
  } else if (n == 0) {
    print('$n is zero');
  } else {
    print('$n is positive');
  }
}

2.Question
=>which one is greater in a and b?
code:-

import 'dart:io';

void main() {
  print('Om Namah Shivay');
  print(greater());
}

int greater({int? a, int? b}) {
  a = int.parse(stdin.readLineSync()!);
  b = int.parse(stdin.readLineSync()!);
  if (a > b) {
    return a;
  } else {
    return b;
  }
}

3.Question
Find that the alphabet is in lowercase or uppercase?
code:-

void main() {
  print('Om Namah Shivay');
  print(Case(alpphabet: 'om'));
}

String Case({required String alpphabet}) {
  if (alpphabet == alpphabet.toUpperCase()) {
    return 'upperCase';
  } else {
    return 'lowerCase';
  }
}

loops
4.print 1 to n
code:-

void main() {
  print('Om Namah Shivay');
  number(n: 10);
}

void number({required int n}) {
  int i = 1;
  while (i <= n) {
    print(i);
    i++;
  }
}

5.print sum of 1 to n?

void main() {
  print('Om Namah Shivay');

  print(sum(n: 5));
}

int sum({required int n}) {
  int i = 1, sum = 0;

  while (i <= n) {
    sum += i;
    i++;
  }
  return sum;
}

6.Find sum of even numbers in 1 to n?

code:-

void main() {
  print('Om Namah Shivay');

  print(sum(n: 5));
}

int sum({required int n}) {
  int i = 1, sum = 0;

  while (i <= n) {
    i % 2 == 0 ? sum += i : sum += 0;

    i++;
  }
  return sum;
}

7.convert f to c(temp.)
code:-

void main() {
  print('Om Namah Shivay');

  print(celsiusConvertor(f: 5.23));
}

double celsiusConvertor({required double f}) {
  return (f - 32) * 5 / 9;
}

8.n is prime or not?

code:-

void main() {
  print('Om Namah Shivay');

  print(prime(n: 56));
}

String prime({required double n}) {
  int i = 2;
  String ans = 'prime';
  while (i < n) {
    if (n % i == 0) {
      ans = 'non-prime';
      break;
    }
  }
  return ans;
}

9.Make this pattern

code:-

void main() {
  print('Om Namah Shivay');

  print(pattern());
}

String pattern() {
  int i = 1;
  String star = '*';
  while (i <= 3) {
    print(star * 4);
    i++;
  }
  return '';
}

10.Make this pattern

111
222
333

code:-

void main() {
  print('Om Namah Shivay');

  print(pattern());
}

String pattern() {
  int i = 1;
  while (i <= 3) {
    String star = i.toString();

    print(star * 3);
    i++;
  }
  return '';
}

I understood