convert large number to spoken english

Question

Converting 'small' numbers to English is not to troublesome. But if you handle BCMath Arbitrary Precision numbers then it can be.

Using code from:

http://marc.info/?l=php-general&m=99928281523866&w=2

The maximum number seems to be:

two billion one hundred forty seven million four hundred eighty three thousand six hundred forty seven

Anyone know a function to convert numbers bigger than that?

Answer 1

You have to write your own function, I suggest to use numbers as a string, let a substract like this:

    $string =  "12356";
    $text="";
    // level means 0-ones, 1- thousand , 2 million, 3 billion etc...
    $level=0;
    //until string has no character left
    while ($len=getval($string)){
      // get partial number from 0 to 999
      $string_partial = substr($string, (strlen($string)-$len)) ;
      // get hundreds
      $hund = ($string_partial - ($string_partial % 100))/100;
      // get tens
      $tens = $string_partial - ($hund *100);
      $tens = ($tens - ($tens %10))/10;
      // get ones
      $ones = $string_partial - ($tens*10) - ($hund*100);
      // remove partial_string form original string             
      $string = substr($string, 0, (strlen($string)-$len));
      // edbug echoing
      echo $level . " - " . $hund. " - " . $tens .  " - " . $ones . "<br>";
      // you need to create a function that convert number to text only from 0 to 999 to set correct million/thousand etc, use $level.
      //$text = getTextvalue($hund,$tens,$ones,$level).$text;
      //increment $level
      $level++;
    }
    function getval($n){
      switch (strlen($n)){
       case 0: return false;
       case 1: return 1;
       case 2: return 2;
       default: return 3;
       }
    }

example:

$string =  "123456789";

will output

 $level - $hund - $tens - $ones
 0 - 7 - 8 - 9  
 1 - 4 - 5 - 6  //thousand
 2 - 1 - 2 - 3  //million

Answer 2

I wrote the vpi2english function to handle integers as large as 10^306 - 1. It is part of my VPI toolbox.

vpi2english(vpi('12000000110022987')) 
ans = 
twelve quadrillion, one hundred ten million, twenty two thousand, nine hundred eighty seven

Answer 3

For numbers larger than PHP_MAX_INT, you'll have to either write the function on rely on an external service, such as WolframAlpha.

The only functionality PHP offers for this is Intl's NumberFormatter. NumberFormatter::format accepts floats, but this means it can only handle integers up to 2^63-1 in 64-bit long architectures or 52-bit numbers in 32-bit ones.