Download - The Bastards Book of Regular Expressions

Negative character setsNow that we know how to include sets of characters in our patterns, let’s see how to exclude them.The syntax is simple and easy to remember. But it opens up a new range of regex possibilities. Sothis chapter will re-emphasize the concepts we’ve covered so far while mixing in new tricks thatcome from thinking negatively.With the square-bracket notation, we are able to specify a set or range of characters to match:Find [bcd]ogMatches “bog” or “cog” or “dog”But what if we want to match anything but those terms, such as “fog” or “hog”?Negative character setsTo exclude a set of characters from a pattern, use the same square bracket notation as a normalcharacter set, but use a caret symbol, ˆ, directly after the left-bracket.The following regex:[^abcd]– will match any character except a literal a, b, c, or dThis regex:[^0-5]– matches any character that is not the numbers 0 through 5.Let’s revisit a previous exercise in which we removed all the non-number/decimal characters:75