Syntax
`text ${expression} more text`Examples
String Interpolation
Embedding variables and expressions directly inside a string.
const name = "Alice";
const age = 25;
// Old way
console.log("Hello, " + name + "! You are " + age + " years old.");
// Template literal way
console.log(`Hello, ${name}! You are ${age} years old.`);
// Expressions work too, not just variables
console.log(`Next year you will be ${age + 1}.`);Multi-line Strings
Writing strings that span multiple lines without escape characters.
const message = `This is line one.
This is line two.
This is line three.`;
console.log(message);
// Useful for building small HTML snippets too
const html = `<div class="card">
<h2>${name}</h2>
<p>Age: ${age}</p>
</div>`;Best practices
- Prefer template literals over string concatenation with + for anything involving variables
- Use them for multi-line strings instead of manually inserting \n characters
- Keep embedded expressions simple - move complex logic out into a variable before interpolating it
- Remember template literals are still just strings - they do not automatically escape HTML, which matters for security when inserting user input into the DOM
At a glance
- Purpose
- Application logic and interaction
- File extension
- .js ยท .mjs
- Runs in
- Browsers and JavaScript runtimes
- Usually used with
- HTML, CSS and Web APIs
Specifications & further reading
Related JavaScript documentation
Arrow Functions
Arrow functions provide a more concise syntax for writing function expressions in JavaScript. Introduced in ES6, they use the => syntax and have some important differences from regular functions, particularly in how they handle the "this" keyword. Arrow functions are especially useful for callbacks, array methods, and short inline functions.Variables: var, let, const
JavaScript has three ways to declare variables. var is the original way, function-scoped and hoisted with a default value of undefined. let, introduced in ES6, is block-scoped and can be reassigned. const is also block-scoped but cannot be reassigned after its initial value is set. Modern JavaScript strongly favors let and const over var.Data Types
JavaScript has seven primitive data types - string, number, boolean, undefined, null, bigint, and symbol - plus the object type, which includes arrays, functions, and plain objects. JavaScript is dynamically typed, meaning a variable can hold any type and that type can change. The typeof operator reports a value's type at runtime.Arithmetic Operators
Arithmetic operators perform mathematical calculations on numbers: addition (+), subtraction (-), multiplication (*), division (/), remainder/modulo (%), and exponentiation (**). The + operator also performs string concatenation when either operand is a string. Increment (++) and decrement (--) adjust a variable by one.
Arrow functions provide a more concise syntax for writing function expressions in JavaScript. Introduced in ES6, they use the => syntax and have some important differences from regular functions, particularly in how they handle the "this" keyword. Arrow functions are especially useful for callbacks, array methods, and short inline functions.Variables: var, let, const
JavaScript has three ways to declare variables. var is the original way, function-scoped and hoisted with a default value of undefined. let, introduced in ES6, is block-scoped and can be reassigned. const is also block-scoped but cannot be reassigned after its initial value is set. Modern JavaScript strongly favors let and const over var.Data Types
JavaScript has seven primitive data types - string, number, boolean, undefined, null, bigint, and symbol - plus the object type, which includes arrays, functions, and plain objects. JavaScript is dynamically typed, meaning a variable can hold any type and that type can change. The typeof operator reports a value's type at runtime.Arithmetic Operators
Arithmetic operators perform mathematical calculations on numbers: addition (+), subtraction (-), multiplication (*), division (/), remainder/modulo (%), and exponentiation (**). The + operator also performs string concatenation when either operand is a string. Increment (++) and decrement (--) adjust a variable by one.