Re: How to extract digits by position in a string?



On Wed, Apr 9, 2008 at 4:31 PM, Jialin Li <jialinli1981@xxxxxxxxx> wrote:
substr($string,0,2) will give you the first two digits
substr($string,5,1) will give you the sixth digit.
snip

There are at least three downsides to using the substr function:
1. multiple function calls
2. lots of typing
3. no guarantee that the input string is in the right format

The substr function is useful, but regexes and the unpack function are
much better for most cases. One case where the substr function is
better than a regex is the extraction of a substring from the end of a
string which may have a variable length (i.e. fixed length regexes
that are anchored only at the end of the string).

--
Chas. Owens
wonkden.net
The most important skill a programmer can have is the ability to read.
.