Moving decimal from the right in PHP

问题

I have large numbers and their decimals points. Here are some examples and what should return:

Number: 300000
Decimals: 8
Should return: 0.00300000

Number: 700000000
Decimals: 8 
Should return: 7


Number: 800000000
Decimals: 6
Should return: 800

At the moment I'm doing this:

substr($number, 0, abs($decimals + 1))

But it returns 0 if the number of decimals is superior to the number of digits in the number (example one returns 0).

Any idea how to do this?

回答1:

Divide by 10 to the power of the number of decimals:

$result = $number / (10 ** $decimals);

回答2:

Divide by ten to the power of decimals?

$n = 700000000;
$d = 8;

Echo $n/pow(10,$d);

https://3v4l.org/MdoW1

来源：https://stackoverflow.com/questions/47143473/moving-decimal-from-the-right-in-php