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How can I use closures in JavaScript to create private variables within a function?

Asked on Oct 06, 2025

Answer

Closures in JavaScript allow you to create private variables by enclosing them within a function scope, making them inaccessible from outside that function. Here's a simple example demonstrating this concept.

<!-- BEGIN COPY / PASTE -->
        function createCounter() {
            let count = 0; // Private variable

            return {
                increment: function() {
                    count++;
                    return count;
                },
                decrement: function() {
                    count--;
                    return count;
                },
                getCount: function() {
                    return count;
                }
            };
        }

        const counter = createCounter();
        console.log(counter.increment()); // 1
        console.log(counter.increment()); // 2
        console.log(counter.decrement()); // 1
        console.log(counter.getCount());  // 1
        <!-- END COPY / PASTE -->

Additional Comment:

The "createCounter" function defines a private variable "count" that is not accessible directly from outside.
The returned object contains methods that form closures over the "count" variable, allowing controlled access and modification.
This pattern is useful for encapsulating data and restricting direct access, promoting data integrity.

✅ Answered with JavaScript best practices.

Ask any question about JavaScript here... and get an instant response.

How can I use closures in JavaScript to create private variables within a function?

Asked on Oct 06, 2025

Answer

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