src/Peach/DF/JsonCodec.php
private function encodeFloat($var)
    {
        $str = strval($var);
        if (!$this->getEncodeOption(self::PRESERVE_ZERO_FRACTION)) {
            return $str;
        }
        if (false !== strpos($str, "E")) {
            return $str;
        }
        return (floor($var) === $var) ? "{$str}.0" : $str;
    }
private function encodeFloat($var)
    {
        $str = strval($var);
        if (!$this->getEncodeOption(self::PRESERVE_ZERO_FRACTION)) {
            return $str;
        }
        if (false !== strpos($str, "E")) {
            return $str;
        }
        return (floor($var) === $var) ? "{$str}.0" : $str;
    }
float 値を文字列に変換します.

@param  float $var 変換対象の float 値
@return string     変換結果