space Character Class
What is [[:space:]]?
Explanation
This character class identifies all space characters like "f" -form feed, "n"- newline, "r"- carriage return, "t" - tab, "v" -vertical tab.
<?php
$chr = '23asd fgshgf';
$det = ereg_replace("[[:space:]]","X", $chr);
echo $det;
?> Result :
23asdXfgshgf
In the above example this regular expression is used with [[:alnum:]], along with "|" or operator to identify the presence of any space or alpha numeric character in the given string, and the string has all these characters, so its matched.
#! C:programfilesperlbinperl
print "content-type: text/htmlnn";
$str = "sfg jh s@";
if ( $str =~ /[[:space:]]{2,4}/)
{print "Matches!";}
else
{print "Unmatch!";} Result :
Unmatch!
In the above example the pattern "[[:space:]]{2,4}" identifies consecutive spaces that should be above "2" and with a minimun of "4", so its unmatched as the string has single space.
PHP Example:
<?php
$chr = '23asd fgshgf';
$det = ereg_replace("[[:space:]]","X", $chr);
echo $det;
?>
23asdXfgshgf
In the above example this regular expression is used with [[:alnum:]], along with "|" or operator to identify the presence of any space or alpha numeric character in the given string, and the string has all these characters, so its matched.
Perl Example:
#! C:programfilesperlbinperl
print "content-type: text/htmlnn";
$str = "sfg jh s@";
if ( $str =~ /[[:space:]]{2,4}/)
{print "Matches!";}
else
{print "Unmatch!";}
Unmatch!
In the above example the pattern "[[:space:]]{2,4}" identifies consecutive spaces that should be above "2" and with a minimun of "4", so its unmatched as the string has single space.
