What is a callback function in JavaScript?
a) A function passed as an argument to another function
b) A function that returns multiple values
c) A function that runs in the background
d) A function that loops indefinitely
Answer:
a) A function passed as an argument to another function
Explanation:
A callback function is a function passed as an argument to another function and is invoked after the completion of that function. Callbacks are commonly used for asynchronous programming in JavaScript.
Example:
function greeting(name) {
console.log("Hello " + name);
}
function processUserInput(callback) {
let name = "John";
callback(name);
}
processUserInput(greeting); // Output: "Hello John"