Regular Expression: Start from second one

Question

I want to find the second   tag and to start the search from there. How can i do it using regular expressions?

<BR>like <BR>Abdurrahman<BR><SMALL>Fathers Name</SMALL>

alt text

Thank you David. Its because of i woke up early :) – uzay95 Jan 08 '10 at 07:31 — uzay95, Jan 08 '10 at 07:31

score 1 · Accepted Answer · edited May 23 '17 at 12:17

1

Prepend  [^<]*(?= ) to your regex, or remove the lookahead part if you want to start after the second  , such as:  [^<]* .

Find text after the second   but before the third:  [^<]* ([^<]*) 

This finds "waldo" in  404 waldo .

Note: I specifically used the above instead of the non-greedy .*? because once the above starts not working for you, you should stop parsing HTML with regex, and .*? will hide when that happens. However, the non-greedy quantifier is also not as well-supported, and you can always change to that if you want.

edited May 23 '17 at 12:17

Community

1
1

answered Jan 08 '10 at 08:13

Note that `
[^<]*
` is not the same as `
.*?
`. – Gumbo Jan 08 '10 at 08:17
Very good answer. Thank you but i want to ask 1 more question. This is very good >[^<]* generates this result '>like' . But i want to remove '>' tag from the result. So i just want to have 'like' result. How can i do this? – uzay95 Jan 08 '10 at 08:18
@Gumbo, but they have same result. – uzay95 Jan 08 '10 at 08:19
uzay95: I don't understand what you mean. – Jan 08 '10 at 08:19
uzay95: No, they are different, and I believe you should use what I answered, for the stated reason. – Jan 08 '10 at 08:20
@Roger Pate, first i've edited my first comment to express myself better so that i can get "like" word. And could you please tell why they are different? – uzay95 Jan 08 '10 at 08:31
uzay95: I still don't understand what you mean. Could you give example input. actual behavior, and desired behavior? --- They are different when you try to parse HTML, such as this input: `
abc
def
ghi
jkl
`. – Jan 08 '10 at 08:35
Look, this my target string:
like
Abdurrahman
Fathers Name and when I write " >[^<]* " the result is equal to : '>like' As you can see, it includes an undesired character which is " > ". I don't want that. All I am asking is, where am I making a mistake? How can I get my code to just get the word "like" and nothing else. – uzay95 Jan 08 '10 at 08:42
To get "like " and nothing else from `
like
Abdurrahman
Fathers Name`, use: `
([^<]*)
`. – Jan 08 '10 at 08:46
To get "Abdurrahman" from `
like
Abdurrahman
Fathers Name`, use: `
[^<]*
([^<]*)
`. – Jan 08 '10 at 08:46
Roger, I really thank you for your patient comments. I've just tried the code you suggested and it seems to return/highlight/include the
and codes as well. So, I was trying to get rid of ">" character but now I have even more to get rid of. So unfortunately it didn't do what I wanted it to do. I apologize for repeating it again and again but isn't there a way to just highlight the word "like" ? – uzay95 Jan 08 '10 at 09:00
There's multiple levels of matching, your program is showing the complete matched text, while you're interested in the first group here (the part between the parentheses); get your program to show you the difference between those. – Jan 08 '10 at 09:32

Brian Campbell · Answer 2 · 2010-01-08T08:33:47.583

The usual solution to this sort of problem is to use a "capturing group". Most regular expression systems allow you to extract not only the entire matching sequence, but also sub-matches within it. This is done by grouping a part of the expression within ( and ). For instance, if I use the following expression (this is in JavaScript; I'm not sure what language you want to be working in, but the basic idea works in most languages):

var string = "<BR>like <BR>Abdurrahman<BR><SMALL>Fathers Name</SMALL>";
var match = string.match(/<BR>.*?<BR>([a-zA-Z]*)/);

Then I can get either everything that matched using match[0], which is " like Abdurrahman", or I can get only the part inside the parentheses using match[1], which gives me "Abdurrahman".

I'm not sure exactly what you are looking for. You might want to clarify your question. This shows you how to find two `
` tags, followed by whatever else you put in the parentheses. For instance, if you are looking for "Father", the search would be `
.*?
.*(Father)`, and the first substring match would refer to where it found `Father`. http://rubular.com/regexes/12836 — Brian Campbell, Jan 08 '10 at 08:06

score 0 · Answer 3 · answered Jan 08 '10 at 08:00

assuming you are using PHP, you can split your string on   using explode

$str='<BR>like <BR>Abdurrahman<BR><SMALL>Fathers Name</SMALL>';
$s = explode("<BR>",$str,3);
$string = end($s);
print $string;

output

$  php test.php
Abdurrahman<BR><SMALL>Fathers Name</SMALL>

you can then use "$string" variable and do whatever you want.

The steps above can be done with other languages as well by using the string splitting methods your prog language has.

score 0 · Answer 4 · answered Jan 08 '10 at 08:17

0

this regular expression should math the first two  s:

/(\s*<br\s*/?>\s*){2}/i

so you should either replace them with nothing or use preg_match or RegExp.prototype.match to extract the arguments.

In JavaScript:

var afterReplace = str.replace( /(\s*<br\s*\/?>\s*){2}/i, '' );

In PHP

$afterReplace = preg_replace( '/(\s*<br\s*\/?>\s*){2}/i', '', $str );

I'm only sure it'll work in PHP / JavaScript, but it should work in everything...

answered Jan 08 '10 at 08:17

Dan Beam

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Would you tell me please what is the meaning of this reges '/(\s*
\s*){2}/i' I just want to learn. – uzay95 Jan 08 '10 at 08:21
Dan: That won't match given input text of `
anything here
`, because you don't allow for anything but `\s` between the tags. – Jan 08 '10 at 08:27
to explain /(\s*
\s*){2}/i / # start regex ( # start group \s # whitespace * # any number of previous (inc. zero)
# literal \s # whitespace * # zero or more of the previous ) # end group {2} # 2 of the group / # end regex i # match non-case sensitively (sorry my spacing is lost) – ternaryOperator Jan 08 '10 at 14:55

Regular Expression: Start from second one

4 Answers4