| Re: reduce all spaces to one [message #176904 is a reply to message #176903] |
Sat, 04 February 2012 14:57   |
Jerry Stuckle
Messages: 2598
Registered: September 2010
Karma:
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Senior Member |
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On 2/4/2012 9:41 AM, Thomas 'PointedEars' Lahn wrote:
> John wrote:
>
>> Am 03.02.2012 21:19, schrieb M. Strobel:
>>> Solution shootout:
>>> strobel@s114-intel:~> php -a
>>> Interactive shell
>>>
>>> php> echo str_replace(' ',' ','here are some spaces ');
>>> here are some spaces
>>> php> echo preg_replace('/\s+/', ' ', 'here are some spaces ');
>>> here are some spaces
>>> php>
>>>
>>> The regex solution is the winner.
>>
>> OK. Thanks to all those who answered !!
>
> It should be noted that if your question was understood literally, the
> solutions presented so far would be wrong. \s would match too many
> different characters, as it stands for *white-space* in PCRE, _not_ only the
> space character. In order to reduce only all consecutive *space* characters
> to one space character, you need to write
>
> echo preg_replace('/ +/', ' ', "here are some \n spaces ");
>
> Note that the newline, which is white-space too, is preserved here.
>
Newline is preserved in my version also, if you understood ANYTHING
about how PHP's regex's work (but we already know you don't). It also
takes out tabs - which may be inserted automatically by some editors,
for instance, and can be desirable.
> If you want to make the space character in the expression better visible,
> you can use
>
> (1) echo preg_replace('/\ +/', ' ', "here are some \n spaces ");
>
The search pattern is invalid.
> or
>
> (2) echo preg_replace('/\\ +/', ' ', "here are some \n spaces ");
>
Searches for the sequence '\ '
> or
>
> (3) echo preg_replace('/\x20+/', ' ', "here are some \n spaces ");
>
Ugh!
> or
>
> (4) echo preg_replace('/\\x20+/', ' ', "here are some \n spaces ");
>
Again, invalid escape sequence.
> Your approach,
>
> echo preg_replace('/[ ]+/', ' ', "here are some \n spaces ");
>
> is equivalent to that, but slightly less efficient because of the character
> class (even in Visual Basic .NET). However, it also has the advantage over
> the simple solutions (1) and (2) that multiple spaces in the character class
> will still only match one space.
>
>
> PointedEars
Showing your ignorance again. You do better when you keep your mouth shut.
--
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Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
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