Want to find and remove word only from string using - PHP

Question

I hav especific need of removing word from string, But I am having problem when that word has dot (.) character.

Lets see here is the string and what I have tried so far?

$result = 'Hello Ka Kashish.';
$result = preg_replace('/\bKa\b/i', '', $result);

I will get the expected result 'Hello Kashish.'

But if the string is like below, It is not working

$result = 'Hello Ka. Kashish.';
$result = preg_replace('/\bKa.\b/i', '', $result);

It gives me result 'Hello Ka. Kashish.' Why this .(dot) is not working? Please give me solution.

And if I can achive this word removal in any other way, pLease let me know. I want to remove only word not set of charaters, as 'Ka' word will be removed, but 'Ka' will not be removed from 'Kashish'. Please help me.

Thanks in Advance

Answer 1

This is because the dot can match any character.

The problem, too, is that \b really matches a word frontier, ie a position where a word character is followed by a non word character, or a non word character is followed by a word character. But as a dot is not a word character and neither is a space for that matter, it won't match.

Maybe you should try that instead:

preg_replace('/\bKa(\W|$)/i', '', $result)

Answer 2

The reason is that \b represents a word boundary. I.e. a boundary between a word character and a non-word character. See http://www.regular-expressions.info/wordboundaries.html

The boundary between a full stop "." and a space " " is not a word boundary, so the pattern match fails. Neither "." nor a back-slashed "." will work. You need to remove the second "\b".

Separately, "." means "any character", so the purpose of using back-slash "." is to ensure it matches only a full-stop, as others have pointed out. This is important to note when re-designing your pattern to work without the second "\b".

Answer 3

You need to escape the dot i.e. . instead of .

preg_replace('/\bKa\.\b/i', '', $result); 

Answer 4

perhaps this will work the way you want it to?

preg_replace('/\bKa[\.]?(\s|$)/i', '', $result);

Answer 5

Here is a lookahead based regex that will work for your case:

$result = 'Ka. Hello Ka. Kashish. Ka.';
$result = preg_replace('/(?<=\b)Ka\.(?=(\W|$))/i', '', $result);

OUTPUT:

string(17) " Hello  Kashish. "

Answer 6

rtrim is used to remove selected characters from right side of the string.

Here is an example of how to remove dot from the end of the sentence:

$result1=rtrim($result, '.');
echo $result1;