Regular expressions also commonly known as regex or regexp, are sequences of characters that define a search pattern.
They are used to match patterns within strings and are invaluable tools for text processing and manipulation.
Regular expressions can be used with string methods. The method regexp.test(stringValue) checks if there is at least one match in the string stringValue. If a match is found, it returns true, otherwise it returns false.
In regex, for matching exact characters, we can use the syntax /.../.
Let's consider a simple example where we want to check if a string contains the word shells.
Similarly, the string.match() method can be used to find all matches of a regular expression in a string.
Let's consider an example where we want to find all occurrences of the word apple in a string: