Question

What are regular expression patterns in Javascript?

Answer 1

Regular Expressions provide a group of patterns in order to match characters. Basically they are categorized into 3 types,

1. Brackets: These are used to find a range of characters. For example, below are some use cases,
   1. [abc]: Used to find any of the characters between the brackets(a,b,c)
   2. [0-9]: Used to find any of the digits between the brackets
   3. (a|b): Used to find any of the alternatives separated with |
2. Metacharacters: These are characters with a special meaning For example, below are some use cases,
   1. \d: Used to find a digit
   2. \s: Used to find a whitespace character
   3. \b: Used to find a match at the beginning or ending of a word
3. Quantifiers: These are useful to define quantities For example, below are some use cases,
   1. n+: Used to find matches for any string that contains at least one n
   2. n*: Used to find matches for any string that contains zero or more occurrences of n
   3. n?: Used to find matches for any string that contains zero or one occurrences of n