What is string interpolation javascript?

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String interpolation in JavaScript is a powerful feature that allows developers to embed expressions within string literals. It provides a concise and efficient way to combine variables, functions, or expressions with strings, making the code more readable and maintainable. This article will delve into the concept of string interpolation in JavaScript, exploring its syntax, benefits, and practical examples.

Syntax of String Interpolation

In JavaScript, string interpolation is achieved using template literals, which are enclosed within backticks (`). To interpolate a value or expression within a string, you need to use the `${}` syntax. Let’s take a look at a simple example:

const name = ‘John’;
const age = 25;

const message = `My name is ${name} and I am ${age} years old.`;

In the above code, the variables `name` and `age` are interpolated within the string `message` using `${}`. When the code is executed, the output will be:

My name is John and I am 25 years old.

The expressions within `${}` are evaluated and their values are inserted into the string.

Benefits of String Interpolation

1. Readability: String interpolation enhances code readability by allowing developers to directly embed variables and expressions within strings. This eliminates the need for complex concatenation or escaping characters.

2. Code Maintainability: Interpolated strings are easier to maintain as they provide a clear separation between static text and dynamic values. When variables or expressions change, you only need to update them in one place, reducing the chances of errors.

3. Multiline Strings: Template literals also support multiline strings, which can be useful when dealing with lengthy text or HTML templates. By using string interpolation, multiline strings can be created without the need for manual line breaks or concatenation.

Advanced String Interpolation Techniques

Apart from simple variable interpolation, JavaScript also supports more advanced techniques within template literals.

1. Expression Evaluation: You can perform complex calculations or function calls within `${}`. For example:

const x = 5;
const y = 10;

const result = `The sum of ${x} and ${y} is ${x + y}.`;

The output will be:

The sum of 5 and 10 is 15.

2. Object Property Access: Template literals can also be used to access object properties directly within the string. For instance:

const person = {
name: ‘Alice’,
age: 30

const message = `My name is ${person.name} and I am ${person.age} years old.`;

The output will be:

My name is Alice and I am 30 years old.


String interpolation in JavaScript, achieved through template literals, provides a convenient way to combine variables, expressions, and object properties within strings. It improves code readability, maintainability, and supports advanced techniques like expression evaluation and object property access. By leveraging string interpolation, developers can write more concise and expressive code.


– developer.mozilla.org
– www.w3schools.com