bcsub
(PHP 4, PHP 5, PHP 7, PHP 8)
bcsub — 两个任意精度数字的减法
参数
num1
-
左操作数,字符串类型。
num2
-
右操作数,字符串类型。
scale
-
此参数用于设置结果中的小数位数。如果为
null
,则使用 bcscale() 设置的默认小数位数,或者回退到bcmath.scale
INI 指令的值。
返回值
以 string 类型返回减法之后的结果。
更新日志
版本 | 说明 |
---|---|
8.0.0 |
现在 scale 可以为 null。
|
示例
示例 #1 bcsub() 示例
<?php
$a = '1.234';
$b = '5';
echo bcsub($a, $b); // -3
echo bcsub($a, $b, 4); // -3.7660
?>
+添加备注
用户贡献的备注 2 notes
nd at snackbox dot org ¶
6 years ago
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.
charles dot adrian dot wood at gmail dot com ¶
5 years ago
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.