Factorial

// Factorial for an Integer 

const number = parseInt(prompt('Enter a Integer :  '));
//condition

if(number < 0){
console.log('Error! Factorial for negative number does not exist.');
}

else if(number == 0) {
console.log(`The factorial of ${number} is 1.`);
}

else { let factorial = 1;
      for(i=1; i<= number; i++) 
      {
      factorial *= i;
      }
      console.log(`The factorial of ${number} is ${fact}.`);
}