String interpolation is a method used in programming to incorporate variable values or expressions within a string. It enables the creation of dynamic strings, where parts of the string’s content can change based on variables or expressions evaluated at runtime.

In string interpolation, placeholders within a string are replaced by the values of variables. For example, you might have a template string with placeholders indicating where to insert values, and the actual output string will replace those placeholders with variable values.

Bash#

In Bash scripting, string interpolation is often done using double quotes to allow variable expansions:

username="Rabi"
echo "Hello, $username!"

This script declares a variable username and then uses it within a string. The $username within the double quotes is replaced by the actual value of username.

JavaScript#

JavaScript uses template literals (strings enclosed by backticks ) for interpolation, which is more straightforward than the older method of string concatenation:

let username = 'Rabi';
console.log(`Hello, ${username}!`);

Python#

Python uses formatted string literals, or f-strings, introduced in Python 3.6:

username = "Rabi"
print(f"Hello, {username}!")