(PHP 4, PHP 5)
bcsub — Subtract one arbitrary precision number from another
Subtracts the right_operand from the left_operand.
The left operand, as a string.
The right operand, as a string.
此可选参数用于设置结果中小数点后的小数位数。 也可通过使用 bcscale() 来设置全局默认的小数位数，用于所有函数。
The result of the subtraction, as a string.
Example #1 bcsub() example
<?php
$a = '1.234';
$b = '5';
echo bcsub($a, $b); // -3
echo bcsub($a, $b, 4); // -3.7660
?>