How To Format String In Javascript

In JavaScript, string formatting is an essential task when displaying data to users or processing text for various purposes. In this blog post, we’ll explore various techniques to format strings in JavaScript. Let’s dive right in!

1. String Concatenation

The most basic method of formatting strings in JavaScript is string concatenation. You can use the + operator to join two or more strings together:

const firstName = "John";
const lastName = "Doe";
const fullName = firstName + " " + lastName;
console.log(fullName); // "John Doe"

2. Template Literals

Introduced in ECMAScript 6 (ES6), template literals are a more elegant and powerful way to format strings. They are surrounded by backticks (`) and allow you to include expressions inside placeholders, denoted by ${expression}:

const firstName = "John";
const lastName = "Doe";
const fullName = `${firstName} ${lastName}`;
console.log(fullName); // "John Doe"

3. String.prototype.concat() Method

The concat() method is a built-in function in the String prototype that can be used to concatenate two or more strings:

const firstName = "John";
const lastName = "Doe";
const fullName = firstName.concat(" ", lastName);
console.log(fullName); // "John Doe"

4. String Padding

ECMAScript 2017 introduced two new methods for string padding: padStart() and padEnd(). These methods can be used to pad a string with a specified character until a given length is reached:

const str = "42";
const paddedStart = str.padStart(5, "0");
const paddedEnd = str.padEnd(5, "0");

console.log(paddedStart); // "00042"
console.log(paddedEnd);   // "42000"

5. Replacing Parts of a String

You can replace parts of a string using the replace() method. The first argument is the string to be replaced, and the second argument is the replacement string:

const str = "Hello, John!";
const newStr = str.replace("John", "Jane");
console.log(newStr); // "Hello, Jane!"


In this blog post, we’ve covered various techniques to format strings in JavaScript, including string concatenation, template literals, string padding, and replacing parts of a string. With these methods in your toolkit, you’ll be well-equipped to tackle any string formatting task in JavaScript. Happy coding!