What is Interpolation in Javascript?

In JavaScript, interpolation is a way to include expressions or variables inside a string. It allows you to construct strings dynamically by embedding the results of expressions directly within the string. This is done using template literals, which are enclosed by backticks (`) instead of single or double quotes.

Here’s a simple example to explain interpolation:

Without Interpolation

Suppose you want to create a greeting message with a name:

let name = "Alice";
let greeting = "Hello, " + name + "!";
console.log(greeting); // Output: Hello, Alice!

In this example, you concatenate strings using the + operator.

With Interpolation

Using interpolation with template literals, the same example can be written more cleanly:

let name = "Alice";
let greeting = `Hello, ${name}!`;
console.log(greeting); // Output: Hello, Alice!

In this example:

• You use backticks (`) to define the string.
• You place the variable name inside ${} within the string.

The ${} syntax allows you to embed any JavaScript expression inside the string, making it easier to read and write complex strings.

Another Example with an Expression

Interpolation can also include expressions, not just variables:

let a = 5;
let b = 3;
let sum = `The sum of ${a} and ${b} is ${a + b}.`;
console.log(sum); // Output: The sum of 5 and 3 is 8.

In this example:

• ${a + b} calculates the sum of a and b and includes the result inside the string.

Interpolation simplifies the process of creating dynamic strings and improves code readability.