Web Dev Homework 1

<?php
//Input Data
$name = "Jason";
$age = 28;

function getPlural($ageArgument){
  if($ageArgument == 1){
      return "";
  } else {
  	return "s";
  }
}

function getOneToNine($age){
	$numbers = array("one", "two", "three", "four", "five", "six", "seven", "eight", "nine");
  //subtract 1 to shift the index
  return $numbers[$age-1];
}

function getStrangeNumbers($age){
	$numbers = array("ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen");
  //subtract 10 to shift the index
  return $numbers[$age-10];
}

function getAboveTwenty($age){
  //split the age into an array of first and second digit
  $parsed = str_split($age);
  
  //create the other words
	$tens = array("twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety");
  
  //the first word is based on the first digit, minus "2" to account for the index
  $firstWord = $tens[$parsed[0] - 2];
  //in other words, give me the first element of $parsed, subtract 2, then give me that element of $tens
  
  //if the second number is a zero we can just return the first word, otherwise we have to get the second number
  if ($parsed[1] == 0){
  	return $firstWord;
  } else {
  	//otherwise lets use our existing code to get the second word:
    return $firstWord . " " . getOneToNine($parsed[1]);
    //so we join the first word with a space to the result of getting 1 to 9
  }
}

function numberLessThanOneHundredToText($age){
  //using <= to prevent negative ages, which are silly
  if($age <= 0){
  	return "zero";
  }else if ($age < 10){
  	return getOneToNine($age);
  }else if ($age < 20){
  	return getStrangeNumbers($age);
  }else{
  	return getAboveTwenty($age);
  }
}

function changeNumberToText($age){
  //using >= here to prevent numbers above 100, which is old.
  if($age >= 100){
  	return "one hundred";
  } else {
  	return numberLessThanOneHundredToText($age);
  }
}

$plural = getPlural($age);
$newAge = changeNumberToText($age);

//Final Output
echo "Happy Birthday $name, you are $newAge year$plural old!";