PHP的两个科学计数法转换为字符串的方法

public function NumToStr($num) {
if (stripos($num, 'e') === false)
return $num;
$num = trim(preg_replace('/[=\'"]/', '', $num, 1), '"'); //出现科学计数法，还原成字符串
$result = "";
while ($num > 0) {
$v = $num - floor($num / 10) * 10;
$num = floor($num / 10);
$result = $v . $result;
}
return $result;
}

function sctonum($num){
if(false !== stripos($num, "e")){
$a = explode("e",strtolower($num));
return bcmul($a[0], bcpow(10, $a[1]));
}
}