Php – n easy way to convert a number to a word in PHP

numbersphp

In PHP, is there an easy way to convert a number to a word? For instance, 27 to twenty-seven.

Best Solution

I found some (2007/2008) source-code online and as it is copyright but I can use it freely and modify it however I want, so I place it here and re-license under CC-Wiki:

<?php
/**
 * English Number Converter - Collection of PHP functions to convert a number
 *                            into English text.
 *
 * This exact code is licensed under CC-Wiki on Stackoverflow.
 * http://creativecommons.org/licenses/by-sa/3.0/
 *
 * @link     http://stackoverflow.com/q/277569/367456
 * @question Is there an easy way to convert a number to a word in PHP?
 *
 * This file incorporates work covered by the following copyright and
 * permission notice:
 *
 *   Copyright 2007-2008 Brenton Fletcher. http://bloople.net/num2text
 *   You can use this freely and modify it however you want.
 */

function convertNumber($number)
{
    list($integer, $fraction) = explode(".", (string) $number);

    $output = "";

    if ($integer{0} == "-")
    {
        $output = "negative ";
        $integer    = ltrim($integer, "-");
    }
    else if ($integer{0} == "+")
    {
        $output = "positive ";
        $integer    = ltrim($integer, "+");
    }

    if ($integer{0} == "0")
    {
        $output .= "zero";
    }
    else
    {
        $integer = str_pad($integer, 36, "0", STR_PAD_LEFT);
        $group   = rtrim(chunk_split($integer, 3, " "), " ");
        $groups  = explode(" ", $group);

        $groups2 = array();
        foreach ($groups as $g)
        {
            $groups2[] = convertThreeDigit($g{0}, $g{1}, $g{2});
        }

        for ($z = 0; $z < count($groups2); $z++)
        {
            if ($groups2[$z] != "")
            {
                $output .= $groups2[$z] . convertGroup(11 - $z) . (
                        $z < 11
                        && !array_search('', array_slice($groups2, $z + 1, -1))
                        && $groups2[11] != ''
                        && $groups[11]{0} == '0'
                            ? " and "
                            : ", "
                    );
            }
        }

        $output = rtrim($output, ", ");
    }

    if ($fraction > 0)
    {
        $output .= " point";
        for ($i = 0; $i < strlen($fraction); $i++)
        {
            $output .= " " . convertDigit($fraction{$i});
        }
    }

    return $output;
}

function convertGroup($index)
{
    switch ($index)
    {
        case 11:
            return " decillion";
        case 10:
            return " nonillion";
        case 9:
            return " octillion";
        case 8:
            return " septillion";
        case 7:
            return " sextillion";
        case 6:
            return " quintrillion";
        case 5:
            return " quadrillion";
        case 4:
            return " trillion";
        case 3:
            return " billion";
        case 2:
            return " million";
        case 1:
            return " thousand";
        case 0:
            return "";
    }
}

function convertThreeDigit($digit1, $digit2, $digit3)
{
    $buffer = "";

    if ($digit1 == "0" && $digit2 == "0" && $digit3 == "0")
    {
        return "";
    }

    if ($digit1 != "0")
    {
        $buffer .= convertDigit($digit1) . " hundred";
        if ($digit2 != "0" || $digit3 != "0")
        {
            $buffer .= " and ";
        }
    }

    if ($digit2 != "0")
    {
        $buffer .= convertTwoDigit($digit2, $digit3);
    }
    else if ($digit3 != "0")
    {
        $buffer .= convertDigit($digit3);
    }

    return $buffer;
}

function convertTwoDigit($digit1, $digit2)
{
    if ($digit2 == "0")
    {
        switch ($digit1)
        {
            case "1":
                return "ten";
            case "2":
                return "twenty";
            case "3":
                return "thirty";
            case "4":
                return "forty";
            case "5":
                return "fifty";
            case "6":
                return "sixty";
            case "7":
                return "seventy";
            case "8":
                return "eighty";
            case "9":
                return "ninety";
        }
    } else if ($digit1 == "1")
    {
        switch ($digit2)
        {
            case "1":
                return "eleven";
            case "2":
                return "twelve";
            case "3":
                return "thirteen";
            case "4":
                return "fourteen";
            case "5":
                return "fifteen";
            case "6":
                return "sixteen";
            case "7":
                return "seventeen";
            case "8":
                return "eighteen";
            case "9":
                return "nineteen";
        }
    } else
    {
        $temp = convertDigit($digit2);
        switch ($digit1)
        {
            case "2":
                return "twenty-$temp";
            case "3":
                return "thirty-$temp";
            case "4":
                return "forty-$temp";
            case "5":
                return "fifty-$temp";
            case "6":
                return "sixty-$temp";
            case "7":
                return "seventy-$temp";
            case "8":
                return "eighty-$temp";
            case "9":
                return "ninety-$temp";
        }
    }
}

function convertDigit($digit)
{
    switch ($digit)
    {
        case "0":
            return "zero";
        case "1":
            return "one";
        case "2":
            return "two";
        case "3":
            return "three";
        case "4":
            return "four";
        case "5":
            return "five";
        case "6":
            return "six";
        case "7":
            return "seven";
        case "8":
            return "eight";
        case "9":
            return "nine";
    }
}

Related Solutions

Php – Enumerations on PHP

Depending upon use case, I would normally use something simple like the following:

abstract class DaysOfWeek
{
    const Sunday = 0;
    const Monday = 1;
    // etc.
}

$today = DaysOfWeek::Sunday;

However, other use cases may require more validation of constants and values. Based on the comments below about reflection, and a few other notes, here's an expanded example which may better serve a much wider range of cases:

abstract class BasicEnum {
    private static $constCacheArray = NULL;

    private static function getConstants() {
        if (self::$constCacheArray == NULL) {
            self::$constCacheArray = [];
        }
        $calledClass = get_called_class();
        if (!array_key_exists($calledClass, self::$constCacheArray)) {
            $reflect = new ReflectionClass($calledClass);
            self::$constCacheArray[$calledClass] = $reflect->getConstants();
        }
        return self::$constCacheArray[$calledClass];
    }

    public static function isValidName($name, $strict = false) {
        $constants = self::getConstants();

        if ($strict) {
            return array_key_exists($name, $constants);
        }

        $keys = array_map('strtolower', array_keys($constants));
        return in_array(strtolower($name), $keys);
    }

    public static function isValidValue($value, $strict = true) {
        $values = array_values(self::getConstants());
        return in_array($value, $values, $strict);
    }
}

By creating a simple enum class that extends BasicEnum, you now have the ability to use methods thusly for simple input validation:

abstract class DaysOfWeek extends BasicEnum {
    const Sunday = 0;
    const Monday = 1;
    const Tuesday = 2;
    const Wednesday = 3;
    const Thursday = 4;
    const Friday = 5;
    const Saturday = 6;
}

DaysOfWeek::isValidName('Humpday');                  // false
DaysOfWeek::isValidName('Monday');                   // true
DaysOfWeek::isValidName('monday');                   // true
DaysOfWeek::isValidName('monday', $strict = true);   // false
DaysOfWeek::isValidName(0);                          // false

DaysOfWeek::isValidValue(0);                         // true
DaysOfWeek::isValidValue(5);                         // true
DaysOfWeek::isValidValue(7);                         // false
DaysOfWeek::isValidValue('Friday');                  // false

As a side note, any time I use reflection at least once on a static/const class where the data won't change (such as in an enum), I cache the results of those reflection calls, since using fresh reflection objects each time will eventually have a noticeable performance impact (Stored in an assocciative array for multiple enums).

Now that most people have finally upgraded to at least 5.3, and SplEnum is available, that is certainly a viable option as well--as long as you don't mind the traditionally unintuitive notion of having actual enum instantiations throughout your codebase. In the above example, BasicEnum and DaysOfWeek cannot be instantiated at all, nor should they be.

Php – Deleting an element from an array in PHP

There are different ways to delete an array element, where some are more useful for some specific tasks than others.

Deleting a single array element

If you want to delete just one array element you can use unset() or alternatively \array_splice().

If you know the value and don’t know the key to delete the element you can use \array_search() to get the key. This only works if the element does not occur more than once, since \array_search returns the first hit only.

`unset()`

Note that when you use unset() the array keys won’t change. If you want to reindex the keys you can use \array_values() after unset(), which will convert all keys to numerically enumerated keys starting from 0.

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
unset($array[1]);
          // ↑ Key which you want to delete

Output:

[
    [0] => a
    [2] => c
]

`\array_splice()` method

If you use \array_splice() the keys will automatically be reindexed, but the associative keys won’t change — as opposed to \array_values(), which will convert all keys to numerical keys.

\array_splice() needs the offset, not the key, as the second parameter.

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
\array_splice($array, 1, 1);
                   // ↑ Offset which you want to delete

Output:

[
    [0] => a
    [1] => c
]

array_splice(), same as unset(), take the array by reference. You don’t assign the return values of those functions back to the array.

Deleting multiple array elements

If you want to delete multiple array elements and don’t want to call unset() or \array_splice() multiple times you can use the functions \array_diff() or \array_diff_key() depending on whether you know the values or the keys of the elements which you want to delete.

`\array_diff()` method

If you know the values of the array elements which you want to delete, then you can use \array_diff(). As before with unset() it won’t change the keys of the array.

Code:

$array = [0 => "a", 1 => "b", 2 => "c", 3 => "c"];
$array = \array_diff($array, ["a", "c"]);
                          // └────────┘
                          // Array values which you want to delete

Output:

[
    [1] => b
]

`\array_diff_key()` method

If you know the keys of the elements which you want to delete, then you want to use \array_diff_key(). You have to make sure you pass the keys as keys in the second parameter and not as values. Keys won’t reindex.

Code:

$array = [0 => "a", 1 => "b", 2 => "c"];
$array = \array_diff_key($array, [0 => "xy", "2" => "xy"]);
                               // ↑           ↑
                               // Array keys which you want to delete

Output:

[
    [1] => b
]

If you want to use unset() or \array_splice() to delete multiple elements with the same value you can use \array_keys() to get all the keys for a specific value and then delete all elements.

Best Solution

Related Solutions

Php – Enumerations on PHP

Php – Deleting an element from an array in PHP

Deleting a single array element

unset()

\array_splice() method

Deleting multiple array elements

\array_diff() method

\array_diff_key() method

Related Question

`unset()`

`\array_splice()` method

`\array_diff()` method

`\array_diff_key()` method