格式化金額，小數位擷取而非四捨五入

<?php



/**
 * @name   小數位擷取格式化金額  例如 100000.00 -> 100,000.00
 * @param  float    $num  [格式化前的金額]
 * @param  integer  $dist [保留的小數位數]
 * @param  BOOL     $zeroComplete [小數位不夠dist時，是否用0補齊] 
 * @return [type]        [description]
 */
if (!function_exists('numberFormat')) {
    function numberFormat($num = 0, $dist =2, $zeroComplete = TRUE) {
        
        if (!preg_match('/^(-?\d+)(\.\d+)?$/', $num)) {
            return $num;
        }
        if ($dist > 4) {
            $dist = 4;
        }else if ($dist <= 0) {
            $dist = 0;
        }
        if (!is_bool($zeroComplete)) {
            $zeroComplete = TRUE;
        }
        $newNum = floor($num * pow(10, $dist)) / pow(10, $dist);
        if (!$zeroComplete) {
            //去掉小數末尾的0 
            $newNum = floatZeroCut($newNum);
            $pos = strpos(strval($newNum), '.');//獲取小數點位置
            if (!$pos) {
                //如果沒找到
                $dist = 0;
            }else {
                $dist = strlen(strval($newNum)) - $pos - 1;
            }
        }
        $result = number_format($newNum, $dist);
        return $result;
    }
}

/**
 * 自動去掉小數末尾的0
 * @param  float  $num [小數]
 * @return float       [返回去掉小數末尾0的小數]
 */
if (!function_exists('floatZeroCut')) {
    function floatZeroCut($num = 0.00) {
        if (!preg_match('/^(-?\d+)(\.\d+)?$/', $num)) {
            return '引數錯誤';
        }
        if ((int)($num) == $num) {
            return $num;
        }
        $strNum = strval($num);
        if (substr($num, -1) == '0'){
            $strNum = substr($strNum, 0, strlen($num) - 1);
            return floatZeroCut(floatval($strNum));
        }else {
            return floatval($strNum);
        }
    }
}