(PHP 4, PHP 5, PHP 7, PHP 8)
bcsub — Subtract one arbitrary precision number from another
Subtracts the num2 from the
num1.
num1The left operand, as a string.
num2The right operand, as a string.
scaleThis optional parameter is used to set the number
of digits after the decimal place in the result. If omitted, it will default to the scale set
globally with the bcscale() function, or fallback to 0 if
this has not been set.
The result of the subtraction, as a string.
| Version | Description |
|---|---|
| 8.0.0 |
scale is now nullable.
|
Example #1 bcsub() example
<?php
$a = '1.234';
$b = '5';
echo bcsub($a, $b); // -3
echo bcsub($a, $b, 4); // -3.7660
?>The parameter order here is probably fairly obvious to most people (subtract right from left), but to clarify with a simple use case since I was struggling with this at the end of a long day:
<?php
echo bcsub('7', '5'); // 7 - 5 = '2'
echo bcsub('12', '17'); // 12 - 17 = '-5'
?>
Provide the parameters in the same order you would when using a normal subtraction operator.Please note that bcsub will fail in non-obvious ways if it's fed something that cannot be converted to a number. For instance:
bcsub('yes', 'no') === '0'
Yes, if you put garbage in, you get garbage out. Just don't expect bcsub to throw an error when you feed it an entirely non-numeric value.