I want to remove substrings from a string. These substrings are always between whitespaces and contain either push or pull.
Let's say I have the following string:
col-md-4 col-sm-6 col-md-pull-6 col-sm-push-4
How would I get the following (using PHP preg_replace)?
col-md-4 col-sm-6
You can do it like this:
$result = preg_replace('~(?:\s*+\S*pu(?:ll|sh)\S*)+~', '', $str);
pattern details:
~ # pattern delimiter
(?: # open a non capturing group
\s*+ # zero or more whitespaces (possessive)
\S* # zero or more non-whitespaces
pu(?:ll|sh) # push or pull
\S*
)+ # repeat the non capturing group (1 or more)
~
Note: if the string begins with "push" or "pull", this pattern may let a leading whitespace, in this case, use rtrim to remove it.
Depending how looks your string, this variant that unrools the loop (?:[^p\s]+|p+(?!u(?:ll|sh)))*+ (that replaces more explicitly \S*) may be more performant:
(?:\s*+[^p\s]*+(?:p+(?!u(?:ll|sh))[^p\s]*)*+pu(?:ll|sh)\S*)+
about possessive quantifiers and lookarounds
pu(?:ll|sh) is this better than push|pull? i mean performance wise?pu two times in the worst case, so you have a small gain.It also removes the spaces which exists before the sub-strings.
\h+\S*\b(?:push|pull)\b\S*|^\S*\b(?:push|pull)\b\S*\h+
Code:
$re = "/\\h+\\S*\\b(?:push|pull)\\b\\S*|^\\S*\\b(?:push|pull)\\b\\S*\\h+/m";
$str = "col-md-4 col-sm-6 col-md-pull-6 col-sm-pull-4\ncol-md-pull-6 foo bar";
$subst = "";
$result = preg_replace($re, $subst, $str);
[^ ]*(?:push|pull)[^ ]*
Try this.Replace by empty string.See demo.
or
\s*[^\s]*(?:push|pull)[^\s]*
https://regex101.com/r/aI4rA5/7
$re = "/[^ ]*(?:push|pull)[^ ]*/m";
$str = "col-md-4 col-sm-6 col-md-pull-6 col-sm-pull-4";
$subst = "";
$result = preg_replace($re, $subst, $str);
push or pull. You used the * for that, right?non space charactes then a push or pull then non space characters.* makes sure non space characters can be from 0 to as many as can`.\s to also match other newline characters?\s will match [ \n\r\t].Added to answer