php 数字转英文格式化

可以使用以下代码实现将数字转换为英文格式：

function numberToWords($number) {
    $words = array(
        0 => 'Zero',
        1 => 'One',
        2 => 'Two',
        3 => 'Three',
        4 => 'Four',
        5 => 'Five',
        6 => 'Six',
        7 => 'Seven',
        8 => 'Eight',
        9 => 'Nine',
        10 => 'Ten',
        11 => 'Eleven',
        12 => 'Twelve',
        13 => 'Thirteen',
        14 => 'Fourteen',
        15 => 'Fifteen',
        16 => 'Sixteen',
        17 => 'Seventeen',
        18 => 'Eighteen',
        19 => 'Nineteen',
        20 => 'Twenty',
        30 => 'Thirty',
        40 => 'Forty',
        50 => 'Fifty',
        60 => 'Sixty',
        70 => 'Seventy',
        80 => 'Eighty',
        90 => 'Ninety'
    );

    if (!is_numeric($number)) {
        return false;
    }

    if (($number >= 0 && (int) $number < 0) || (int) $number < 0 - PHP_INT_MAX) {
        // overflow
        trigger_error(
            'numberToWords only accepts numbers between -' . PHP_INT_MAX . ' and ' . PHP_INT_MAX,
            E_USER_WARNING
        );
        return false;
    }

    if ($number < 0) {
        return 'minus ' . numberToWords(abs($number));
    }

    $string = $fraction = null;

    if (strpos($number, '.') !== false) {
        list($number, $fraction) = explode('.', $number);
    }

    switch (true) {
        case $number < 21:
            $string = $words[$number];
            break;
        case $number < 100:
            $tens = ((int) ($number / 10)) * 10;
            $units = $number % 10;
            $string = $words[$tens];
            if ($units) {
                $string .= ' ' . $words[$units];
            }
            break;
        case $number < 1000:
            $hundreds = $number / 100;
            $remainder = $number % 100;
            $string = $words[$hundreds] . ' Hundred';
            if ($remainder) {
                $string .= ' ' . numberToWords($remainder);
            }
            break;
        case $number < 1000000:
            $thousands = $number / 1000;
            $remainder = $number % 1000;
            $string = numberToWords($thousands) . ' Thousand';
            if ($remainder) {
                $string .= ' ' . numberToWords($remainder);
            }
            break;
        case $number < 1000000000:
            $millions = $number / 1000000;
            $remainder = $number % 1000000;
            $string = numberToWords($millions) . ' Million';
            if ($remainder) {
                $string .= ' ' . numberToWords($remainder);
            }
            break;
        case $number < 1000000000000:
            $billions = $number / 1000000000;
            $remainder = fmod($number, 1000000000);
            $string = numberToWords($billions) . ' Billion';
            if ($remainder) {
                $string .= ' ' . numberToWords($remainder);
            }
            break;
        case $number < 1000000000000000:
            $trillions = $number / 1000000000000;
            $remainder = fmod($number, 1000000000000);
            $string = numberToWords($trillions) . ' Trillion';
            if ($remainder) {
                $string .= ' ' . numberToWords($remainder);
            }
            break;
        default:
            $string = 'Number is too large to convert!';
            break;
    }

    if (null !== $fraction && is_numeric($fraction)) {
        $string .= ' and ' . numberToWords((int) $fraction) . ' cents';
    }

    return $string;
}

然后可以通过以下方式调用该函数：

$number = 123456789;
echo numberToWords($number); // One Hundred Twenty Three Million Four Hundred Fifty Six Thousand Seven Hundred Eighty Nine