Regular Expressions
- Regular expressions are used in programming languages to match parts of strings.
- You create patterns to help you do that matching.
Using the Test method and Match Method
- The
.test()
method only returns a true or false response. - Using the
.match()
method instead will extract the matches. - The
.match()
method is used on Strings rather than Regex.
function alphabetRegex(str) { const regex = /[a-z]/gi; const letters = str.match(regex); return letters.join(' '); } console.log(alphabetRegex('Hello')); // H e l l o
A collection of well-tested and well-performing regexes. You Can import from
@terminus/ngx-tools/regex.
npm I @terminus/ngx-tools
regex only letters
- onlyLettersRegex: Regex requiring only English letters.
import { onlyLettersRegex } from '@terminus/ngx-tools/regex'; onlyLettersRegex.test('Smi3e'); // false onlyLettersRegex.test('Smile'); // true
Here is a great site to help practice and simply see what Regex is matching as you add onto an expression.