no-control-regex.md

Pattern: Control character in regular expression

Issue: -

Description

Control characters (ASCII characters 0-31) are rarely used in JavaScript strings. Regular expressions containing patterns that explicitly match these characters are likely mistakes, as they're special, invisible characters that can cause unexpected behavior.

Examples

Example of incorrect code:

var pattern1 = /\x00/;
var pattern2 = /\x0C/;
var pattern3 = /\x1F/;
var pattern4 = /\u000C/;
var pattern5 = /\u{C}/u;
var pattern6 = new RegExp("\x0C");

Example of correct code:

var pattern1 = /\x20/;
var pattern2 = /\u0020/;
var pattern3 = /\t/;
var pattern4 = /\n/;
var pattern5 = new RegExp("\x20");
var pattern6 = new RegExp("\\n");