Nonvisual constraints

Until now, all the constraints we have been putting on our patterns had to do with characters that could or couldn't be displayed, but Regex provides a number of positional constraints, which allow you to filter out some false positives.

Matching the beginning and end of an input

The first such set is the start and end of string matchers. Using the (^) caret character to match the start of a string and the ($) dollar sign to match the end, we can force a pattern to be positioned in these locations, for example, you can add the dollar sign at the end of a word to make sure that it is the last thing in the provided string. In the next example, I used the /^word|word$/g pattern to match an occurrence of word, which either starts or ends a string. The following image exemplifies the match of the regular expression when given a Text input:

Using both the start and end character together assure that your pattern is the only thing in the string. For example if you have...