The drawback of Using the callback function

The drawback of Using the callback function

Callback function

  • A callback function is a function passed into another function as an argument, which is then invoked inside the outer function to complete some kind of routine or action.
  • Callback functions are used to achieve asynchronous behaviour in JavaScript

    Drawback of using the Callback function

    There are two drawbacks of using the callback function
  • The diamond problem or callback hell
  • Inversion of Control

    The diamond problem / callback hell

  • When we have multiple callbacks nested inside each other then it is called a callback hell
  • Because of this debugging and maintaining the code becomes difficult.
  • It is called a diamond or pyramid problem because nested callbacks look that way Example : Captureasasa.JPG

Inversion of Control / Trust issues with callback

  • Sometimes callback functions do not behave the way they should.
  • One classic example is :
    assume we have a set timeout function which has a timer of 10 sec
    But in the global space we have written so many lines that the time taken to execute those statements is more than 10 sec then as a result the event loop will never find the call stack empty and hence, even after a long time the set timeout has expired the callback function passed inside it will never get executed the way we wanted it to get executed