Numbers to English

Challenge Difficulty: Medium | Estimated completion time: ~30 minutes

Write a function that accepts a positive integer between 0 and 999 inclusive and returns a string representation of that integer written in English.

Examples

numToEng(0)
output = "zero"
 
numToEng(18)
output = "eighteen"
 
numToEng(126)
output = "one hundred twenty six"
 
numToEng(909)
output = "nine hundred nine"

Notes

• There are no hyphens used (e.g. “thirty five” not “thirty-five”).
• The word “and” is not used (e.g. “one hundred one” not “one hundred and one”).

Solution

Python

def numToEng(number: int) -> str: """ Convert a positive integer (0-999) to its English word representation. Args: number: An integer between 0 and 999 inclusive. Returns: String representation of the number in English words. Examples: >>> numToEng(0) 'zero' >>> numToEng(18) 'eighteen' >>> numToEng(126) 'one hundred twenty six' """ if number == 0: return "zero" ones_words = ["", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"] teens_words = ["ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"] tens_words = ["", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"] result_parts = [] # Handle hundreds place hundreds_digit = number // 100 if hundreds_digit > 0: result_parts.append(ones_words[hundreds_digit]) result_parts.append("hundred") # Handle tens and ones places remainder = number % 100 if remainder >= 20: tens_digit = remainder // 10 ones_digit = remainder % 10 result_parts.append(tens_words[tens_digit]) if ones_digit > 0: result_parts.append(ones_words[ones_digit]) elif remainder >= 10: result_parts.append(teens_words[remainder - 10]) elif remainder > 0: result_parts.append(ones_words[remainder]) return " ".join(result_parts) if __name__ <span class="text-highlight"> "__main__": # Test cases assert numToEng(0) </span> "zero" assert numToEng(18) <span class="text-highlight"> "eighteen" assert numToEng(126) </span> "one hundred twenty six" assert numToEng(909) <span class="text-highlight"> "nine hundred nine" assert numToEng(55) </span> "fifty five" assert numToEng(100) <span class="text-highlight"> "one hundred" assert numToEng(999) </span> "nine hundred ninety nine" print("All test cases passed!")

Output