This document provides a regex cheat sheet with examples of how to test regular expressions, match multiple patterns using the OR operator, ignore case using the i flag, and match any character using a wildcard placeholder. It demonstrates testing a regex for a match, using | to match yes, no, or maybe, ignoring case with the i flag, and using . as a placeholder to match words ending in at.

1. REGEX CHEATSHEET
Part 1

2. REGEX
A regular expression, or 'regex', is used to
match parts of a string. Below is my cheat
sheet for creating regular expressions.
Testing a Regex:
Use the .test() method
let testString = "My test string";
let testRegex = /string/;
testRegex.test(testString); // true

3. CHEAT SHEET
A regular expression, or 'regex', is used to
match parts of a string. Below is my cheat
sheet for creating regular expressions.
TESTING MULTIPLE PATTERNS:
Using the OR operator ‘|’
const regex = /yes|no|maybe/;

4. IGNORING CASE:
Using the i flag for case insensitivity
const caseInsensitiveRegex = /ignore case/i;
const testString =
'We use the i flag to iGnOrE CasE';
caseInsensitiveRegex.test(testString); // true
MATCHING ANY CHARACTER:
Using the wildcard character . as a placeholder
// To match "cat", "BAT", "fAT", "mat"
const regexExpr = /.at/gi;
const testString = "cat BAT cupcake fAT mat dog";
const allMatchingWords =
testString.match(regexExpr);
// ["cat", "BAT", "fAT", "mat"]