Why should you care?

Validation and search features often need pattern matching beyond includes().

See it live — copy this example

Paste into an HTML file or the browser console (F12). Use Run below when the live editor is available.

const email = "user@mail.com";
const pattern = /^\w+@\w+\.\w+$/;
console.log(pattern.test(email));

const text = "Order 42 and 99";
console.log(text.match(/\d+/g));

Run Example »

Edit the code below and click Run to see the result in Toolliyo’s live editor.

What happened?

• /pattern/ creates a regex.
• test returns true/false.
• match with g flag finds all digit groups.

Practice next

1. Test email pattern with valid and invalid strings.
2. Use match with g flag on digit groups.
3. Try replace to mask digits.
4. Write a pattern that validates Indian mobile numbers starting with 6–9.
5. Extract domain from an email with capture groups.

Remember

/pattern/ or new RegExp() test, match, replace Flags: g, i, m

ScriptVerse form validation

Signup validates email and PAN format with regex before enabling the submit button.

Outcome: Client-side pattern checks give instant feedback; server still re-validates.