Self-tutoring about regular expressions: the tutor mentions a use of the caret symbol, ^. It seems that, in regular expressions, “^” can mean “not” when it’s the first character inside of square brackets. For example, it seems that [^a-zA-Z] would …
The tutor tells the workings of yesterday’s pattern matching example. In yesterday’s post I mention that the regular expression if ($input=~/item1[^0-9]*[0-9]*.?[0-9]{0,2}/i) can find the pattern item1….$#####.## in a longer string. Here are some explanatory points: =~ is the pattern find …
Perl: regular expressions: yesterday’s code explained Read more »
The tutor demonstrates a Perl regular expression that finds an item name and its price in a string. Suppose you believe that the price of item1 is given in a string, but aren’t sure how exactly it’s said. It could, …
The tutor shows off some of Perl’s pattern matching (aka regex) talents. Let’s imagine you have a laptop you share with a friend for project work. They’re not million-dollar secrets you’re keeping, but on the other hand, you don’t want …
Perl: a password (sort of) using regular expression (regex) power Read more »
The tutor introduces Javascript regex. Regex, aka regular expressions, is a programming concept. One regex function searches input for a given pattern, then reports presence or absence. Another, upon finding the pattern, might change it among the rest of the …