abs()

(PHP 4, PHP 5, PHP 7)

绝对值

说明

返回参数$number的绝对值。

参数

要处理的数字值

返回值

$number的绝对值。如果参数$number是float，则返回的类型也是float，否则返回integer（因为float通常比integer有更大的取值范围）。

范例

Example #1abs()例子

参见

• gmp_abs()Absolute value
• gmp_sign()Sign of number

Result:
1.4061
0.9697
0.2805
Conclusion: better to check before using the feature that the number is less than zero. Even better use multiplication by -1 than this function.

[*EDIT* by danbrown AT php DOT net: Merged user's corrected code with previous post content.]
jeremys indicated one thing - there is no sgn function wich actually seems a bit strange for me. Of course it is as simple as possible, but it is usefull and it is a standard math function needed occasionally.
Well, I have solved this function in a bit different matter:

The difference is that it returns null when the argument isn't a number at all.