BC Math 函数
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bcsub

(PHP 4, PHP 5)

bcsubSubtract one arbitrary precision number from another

说明

string bcsub ( string $left_operand , string $right_operand [, int $scale ] )

Subtracts the right_operand from the left_operand.

参数

left_operand

The left operand, as a string.

right_operand

The right operand, as a string.

scale

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。

返回值

The result of the subtraction, as a string.

范例

Example #1 bcsub() example

<?php

$a 
'1.234';
$b '5';

echo 
bcsub($a$b);     // -3
echo bcsub($a$b4);  // -3.7660

?>

参见


BC Math 函数
在线手册:中文 英文
PHP手册
PHP手册 - N: Subtract one arbitrary precision number from another

用户评论:

info at DONOTSPAM dot ict-eagle dot eu (07-Aug-2009 08:43)

Note that it is almost useless to put a integer higher than 6 maybe 7 in the scale parameter.

In some cases this might be needed. But for the simple souls, more than 4 is not required in most of the time.