Purpose of the 'val' and 'err' functions?

Robert Manolis You mentioned that the var and err were created to allow you to perform operations, and that they are used as a way of reference. But the thing that confuses me is that they were only mentioned once. They were declared at the end of the script and they weren't even a function that served a purpose.. I could understand is var and err were the names of functions that were created and then in the .then and .catch they were being called for performance, but it wasn't even that. They have no purpose its like there was a missing piece of script in this video?

Janelle Mackenzie - What was passed to the .then and .catch were functions. The following code shows two anonymous functions:

val => console.log(val)

err => console.log(err) 

Those functions will log out whatever err and val are. In the case of the video, val would be whatever is returned from the breakfastPromise Promise. And err would be what ever error that happened to occur while trying to resolve the promise. The log statements are being returned from those anonymous functions to demonstrate how you could do something with the val returned from the promise and/or the err, if one were to occur. With err, you might only want to log it out to the console. But with val, you could iterate over it, manipulate it, add it to a DOM element and append it to the DOM, etc.

The first example above could be changed to something like this:

val => {
  if (typeof val  === 'string') {
    document.querySelector('.title').innerHTML = val;
  } 
}

Hope that clears things up a little more.

Hi Robert Manolis , what I have understood is that in .then() and .catch() functions we just pass the value of the resolve() or reject() methods, but what happened here when Guil passed Error('Message') Object with the message, to the .catch(), coz it askes to console.log the err message but instead we have passed the error object, so what is happening over there

Still confused. An anonymous function has no name between the function keyword and parentheses ().so it is generally assigned to a variable so you can call it later. var variableName = function () => {console.log (val)} Yet, in this case, there is no word function, no "( )" , no "{ }" and the word 'val' just pops up. val => console.log (val) Could I write function => console.log(val)? still missing the "( )" and the "{ }".