@ david,
That will return true for any string ending with "INF".
I think substr("$value",0,3) would be more appropriate.
is_infinite
说明
bool is_infinite ( float val )如果 val 为无穷大（正的或负的），例如 log(0) 的结果或者任何超出本平台的浮点数范围的值，则返回 TRUE。
参见 is_finite() 和 is_nan()。
add a note
User Contributed Notes
21-Aug-2006 11:54
david(@t)nirvanis(d@t)org
31-Aug-2004 05:49
31-Aug-2004 05:49
If you have PHP lower than 4.2 you can simulate the behaviour:
function is_infinite($value) {
return (substr("$value",-3) == "INF");
}
(tested on php 4.1.2)