Javascript Regular Expressions

A RegEx Example:

/somepattern/flags

Flags:

/g = global match, so any instances of instead of just first, /i = removes case sensitivity, /m = multiline, /y = sticky

The dot . :

. will match anything, exept line breaks. You can prevent this by escaping \ .

Meta Characters:

probably need to escape these in most cases: [ { ( ) ^ \ $ . | ? * +

Quantifiers

{} can be used like /a{n}/ where we find the letter 'a', n # of times, {n,} at least 'n' times, and {n,m} find at least n times, but no more than 'm' times

\d the digit finder

/\d/ or /[0-9]/ are equivalents, they'll find any digits

\w the alphanumberic and underscore finder

matches any alphanumeric character, equivalent to [A-Za-z0-9_]

\s the whitespace finder

matches a single white space character, including space, tab, form feed, line feed and other unicode spaces. Equivalent to [ \t\r\n].

[abcd] the character set

matches any one of the enclosed characters. You can specify a range of characters by using a hyphen. For example, [abcd] is the same as [a-d].

RegEx Reference

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp