Chapter VI · Functions
Callback Functions
A callback function is passed into another function as an argument to be executed later.
01 How It Works
Think of leaving your phone number so a store clerk can call you when your order arrives.
Higher-order code delegates control back to the provided callback function upon completing an operation.
example.js
function processUser(callback) {
callback("Alice");
}
processUser(name => console.log(name));1. Write a function designed to receive another function parameter.
2. Pass a callback function reference during invocation.
3. Execute the callback inside the host function body.
02 Practical Example
Here is how you might see this concept applied in real-world code:
practical.js
setTimeout(() => {
console.log("Timer callback triggered");
}, 500);Key Takeaway
Callbacks enable asynchronous execution flows and event-driven architectures.