Want regular expression to stop at first occurrence of word

[e_matthes@hotmail.com]

Hello all,

Say I have the following string:

$string = "list of whales: white beluga whale humpback whale atlantic
humpback whale";

I want to pull out the first kind of whale (white beluga). I want
this to work regardless of whether the first whale is a white beluga,
or a humpback, etc. I tried:

$regExp = "/(whales:)(.*)(w hale)/";
$outputArray = array();
if ( preg_match($reg Exp, $string, $outputArray) ) {
print "$outputArr ay[2]<br>";
}

But, the output is "white beluga whale humpback whale atlantic
humpback", as I expected. I know how to stop after finding a single
character, but I can't figure out how to stop after finding a single
instance of a word. Any help? Thanks.

[Heiko Richler]

Re: Want regular expression to stop at first occurrence of word

e_matthes@hotma il.com wrote:

$string = "list of whales: white beluga whale humpback whale atlantic
humpback whale";

$regExp = "/(whales:)(.*)(w hale)/";
if ( preg_match($reg Exp, $string, $outputArray) ) {

But, the output is "white beluga whale humpback whale atlantic
humpback", as I expected. I know how to stop after finding a single
character, but I can't figure out how to stop after finding a single
instance of a word. Any help? Thanks.

RegEx are greedy. That means RegEx match as much as they can. This means
your Expression stops with the last whale. To make it stop with the
first whale make your Expression ungreedey:


$regExp = "/(whales:)(.*?)( whale)/";

or

$regExp = "/(whales:)(.*)(w hale)/U";

see:

http://en.wikipedia.org/wiki/Regular_expression#Greedy_expressions

Heiko
--
http://portal.richler.de/ Namensportal zu Richler
http://www.richler.de/ Heiko Richler: Computer - Know How!
http://www.richler.info/ private Homepage

[e_matthes@hotmail.com]

Re: Want regular expression to stop at first occurrence of word

On Feb 25, 10:25 pm, Heiko Richler <heiko-rich...@nefkom. netwrote:

e_matt...@hotma il.com wrote:

$string = "list of whales: white beluga whale humpback whale atlantic
humpback whale";
$regExp = "/(whales:)(.*)(w hale)/";
if ( preg_match($reg Exp, $string, $outputArray) ) {
But, the output is "white beluga whale humpback whale atlantic
humpback", as I expected. I know how to stop after finding a single
character, but I can't figure out how to stop after finding a single
instance of a word. Any help? Thanks.

>
RegEx are greedy. That means RegEx match as much as they can. This means
your Expression stops with the last whale. To make it stop with the
first whale make your Expression ungreedey:
>
$regExp = "/(whales:)(.*?)( whale)/";
>
or
>
$regExp = "/(whales:)(.*)(w hale)/U";
>
see:http://en.wikipedia.org/wiki/Regular...dy_expressions
>
Heiko
--http://portal.richler. de/Namensportal zu Richlerhttp://www.richler.de/ Heiko Richler: Computer - Know How!http://www.richler.info/ private Homepage

Thank you very much, both for the answer and the reference.

Eric