Create a custom callback in JavaScript

Question

All I need to do is to execute a callback function when my current function execution ends.

function LoadData() 
{
    alert(\'The data has been loaded\');
          


        

Answer 1

When calling the callback function, we could use it like below:

consumingFunction(callbackFunctionName)

Example:

// Callback function only know the action,
// but don't know what's the data.
function callbackFunction(unknown) {
  console.log(unknown);
}

// This is a consuming function.
function getInfo(thenCallback) {
  // When we define the function we only know the data but not
  // the action. The action will be deferred until excecuting.
  var info = 'I know now';
  if (typeof thenCallback === 'function') {
    thenCallback(info);    
  }
}

// Start.
getInfo(callbackFunction); // I know now

This is the Codepend with full example.