JavaScript string guide

JavaScript String Functions

JavaScript string functions help transform, clean, search, split, join, and format text in frontend and Node.js applications.

Common JavaScript String Methods

Frequently used JavaScript string methods include toUpperCase(), toLowerCase(), trim(), replace(), replaceAll(), split(), includes(), startsWith(), endsWith(), and slice().

JavaScript String Examples

Change Case

const text = "Quick Developer Tools";
const upper = text.toUpperCase();
const lower = text.toLowerCase();

Trim Whitespace

const raw = "  customer order  ";
const clean = raw.trim();

Replace Text

const value = "order number";
const slug = value.replaceAll(" ", "-").toLowerCase();

Split and Join

const csv = "json,xml,string";
const parts = csv.split(",");
const joined = parts.join(" | ");

Check Text

const email = "[email protected]";
const hasAt = email.includes("@");
const startsWithDemo = email.startsWith("demo");

Template Literals

const orderId = "ORD-2026-000873";
const message = `Order ${orderId} is ready.`;

Try Text Transformations Online

Use QuickDeveloperTools String Utilities to test case conversion, slug generation, URL encoding, Base64 conversion, line cleanup, duplicate removal, sorting, and text counts before writing JavaScript logic.

Open String Utilities