how to make callback function javascript

How to Make Callback Function in Javascript?

Callback functions are an essential part of Javascript programming. They allow you to execute a function once another function has finished its operation. It is a powerful tool that can help you to write efficient and scalable code. In this article, I will explain how to create a callback function in Javascript.

What is Callback Function

A callback function is a function that is passed as an argument to another function, which is then invoked inside the outer function to complete some kind of routine or action. It is a way of passing a function as an argument to another function, which can then execute the passed function at a suitable time.

How to Create a Callback Function

Creating a callback function in Javascript is simple. Here is an example:

function firstFunction(callback) {
  console.log("First Function: Hello World!");
  callback();
}

function secondFunction() {
  console.log("Second Function: This is a callback function");
}

firstFunction(secondFunction);

In this example, we have two functions; firstFunction and secondFunction. The firstFunction takes a callback function as an argument and executes it at the end of its operation. The secondFunction is passed as an argument to the firstFunction and is executed as a callback function.

Another Way of Creating a Callback Function

Another way of creating a callback function in Javascript is by using anonymous functions. Here is an example:

function firstFunction(callback) {
  console.log("First Function: Hello World!");
  callback();
}

firstFunction(function() {
  console.log("Second Function: This is an anonymous callback function");
});

In this example, instead of creating a separate function, we pass an anonymous function as a callback to the firstFunction.

Conclusion

Callback functions are a powerful tool in Javascript programming. They allow you to execute code in a specific order and make your code more efficient and scalable. By following the examples above, you can create your own callback functions in Javascript and take your programming skills to the next level.