The +, *, ?, and $ flags all follow a character sequence.

Each special character has a specific connotation. The frequency or position of bracketed character sequences and single characters can be denoted by a special character.

The ranges shown above are general you could also use the range to match any decimal digit ranging from 0 through 3, or the range to match any lowercase character ranging from b through v. It matches any character from lowercase a through uppercase Z. It matches any character from uppercase A through uppercase Z. It matches any character from lowercase a through lowercase z.

It matches any decimal digit from 0 through 9. Sr.No.Īny one character not between the brackets. They are used to find a range of characters. Pattern − A string that specifies the pattern of the regular expression or another regular expression.Īttributes − An optional string containing any of the 'g', 'i', and 'm' attributes that specify global, case-insensitive, and multi-line matches, respectively.īrackets () have a special meaning when used in the context of regular expressions. Here is the description of the parameters − Var pattern = new RegExp(pattern, attributes) SyntaxĪ regular expression could be defined with the RegExp () constructor, as follows − The JavaScript RegExp class represents regular expressions, and both String and RegExp define methods that use regular expressions to perform powerful pattern-matching and search-and-replace functions on text.

A regular expression is an object that describes a pattern of characters.

Javascript pattern matching