Mass Variable Decimal Places PHP - php

Question

I know you can tell a variable to go to a certain number of decimal places using:
string number_format ( float $number [, int $decimals = 3 ] )
However, I cannot find a way of doing this en masse for all numbers. Since I have hundreds of variables, all of which need to have the same number of decimal places (whether it means rounding or extending zeros), I would like to be able to just tell it to automatically perform this command across the board instead of typing in the above command for all variables.
Does this function exist, or am I forced to type it all out the long way? Is there maybe a line in the .ini file that I could change if there is no command?
Thanks in advance.
I'm not storing these numbers in a database - I'm echo-ing them on the screen and sending an email.
(There is an equation going on from user input being generated by an HTML form).
The person receiving the email has asked that all numbers be rounded to the third decimal, whether that means rounding off at the thousandths or extending zeros to the thousandths if it only needed whole numbers, tenths, or hundredths. There are literally hundreds of individual variables, i.e. $number1, $number2, etc.

Answer 1

If you are talking about all numbers applied to string variables in your script you could run this line:
if(is_int($value) || is_float($value)){
$value = number_format ( float $number ,3 );
}
Obviously as you reference strings you can also run a similar query to check if your string is a floating numeric:
$values = get_defined_vars();
foreach ($values as $key=>$value){
if(is_string($value) && (float)$value == (string)$value){
$value = number_format ((float)$value , 3 );
}
/***
Save over the original script variables with the edited ones.
Note double dollar
***/
$$key = $value;
}
unset($values,$value,$key);
You could do with reading that in base-2 (computer storage) floating point numbers are inherently stored inaccurately, read http://floating-point-gui.de/ .
Also, really, why would you need this seemingly needless precision?
But then at what stage do you run this command, at the start of your script when the values are mostly empty? Or at the end when the values are mostly been used and no longer active?
I think my answer answers your question but I think that your question does not actually articulate your issue.
In response to the comment / edited qestion:
Simply rather than using $values = get_defined_vars(); use the values from saving the inputs into an array and doing foreach above through the array.
$values = array(array of numbers);
foreach ($values as &$value){
if(is_string($value) && (float)$value == (string)$value){
$value = number_format ((float)$value , 3 );
}
}
unset($value,$key);
This will update all values in the array to being of the spcified numerical placements.

Answer 2

You can use the decimal extension to achieve this, with a central place to create and format. Something like this:
class Number
{
public static function create($value, $precision = Decimal::DEFAULT_PRECISION): Decimal
{
return new Decimal($value, $precision);
}
public static function format(Decimal $decimal, int $places = 3): string
{
return $decimal->toFixed(3);
}
}