了解使用pow / base进行舍入10

There is this function that is used tat I didn't myself create, but at the moment it is only returning the number rounded with 2 decimal places, but I want to change it so it returns it with three; however I don't really understand how it all works.

Here is the function:

function round_number($number, $round = 2)
{
    // we will multiply by 10^$round, then get the floor value of that amount then divide by 10^round.
    ## -> if it does problems, switch back to floor()
    $temp_value = $number * pow(10, $round);
    $temp_value = (!strpos($temp_value, '.')) ? $temp_value : floor($temp_value);
    $number = $temp_value / pow(10, $round);

    return $number;
}

I assume if I change the $round to 3 that it will return correctly?

 // we will multiply by 10^$round, then get the floor value of that amount then divide by 10^round.
## -> if it does problems, switch back to floor()

It says it right in the code what it does!

And yes - changing $round = 3; will work.

However DON'T you should instead just call the function

round_number(12345.12342423, 3);

the number passed in as second parameter (3) will override the $round=2 in the function ($round=2 is the 'default')