Standard Creation

It is recommended to use this form only when creating regex from dynamic variables.

Use when the expression may change or the expression is user generated.

var re = new RegExp(".*");

With flags:

var re = new RegExp(".*", "gmi");

With a backslash: (this must be escaped because the regex is specified with a string)

var re = new RegExp("\\\\w*");

Static initialization

Use when you know the regular expression will not change, and you know what the expression is before runtime.

var re = /.*/;

With flags:

var re = /.*/gmi;

With a backslash: (this should not be escaped because the regex is specified in a literal)

var re = /\\w*/;