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Callback Functions in JavaScript

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Anonymous Function as Arrow Functions

1:58 with Andrew Chalkley

In this video, we'll convert our anonymous function into an arrow function.

Arrow Functions

( ) => {
  console.log("Hello");
}

( ) => console.log("Good bye");

Checkout this workshop on Arrow Functions for more details and examples.

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    Arrow functions are a common way you'll see anonymous functions being written. 0:00
    In this video, we'll convert our anonymous functions into arrow functions. 0:05
    Let's pull out this anonymous function from the executeCallback function. 0:10
    This way, we can see the progression from a regular anonymous function 0:15
    to an arrow function. 0:19
    To convert a function into an arrow function, 0:20
    simply remove the function keyword. 0:24
    And after the parentheses, add an equal sign and a greater than symbol, 0:26
    this is often called a fat arrow. 0:31
    Let's reintroduce the callback into the executeCallback function. 0:34
    Arrow functions have an even shorter syntax, if there's a single line of code, 0:41
    you can remove the curly braces, like so. 0:46
    Why not pause the video and create an arrow function for 0:52
    the goodbye anonymous callback? 0:55
    How did you do, it's pretty straightforward, 1:01
    remove the keyword, and add the fat arrow. 1:06
    You could have gone a step forward and removed the curly braces too, 1:10
    you'd also need to remove the semicolon. 1:17
    You need to remove the semicolon after the console.log statement, 1:22
    because it would terminate the line of code before the last parentheses. 1:26
    If the line of code terminated before the parentheses, 1:31
    the executeCallback function wouldn't get executed. 1:34
    Well done, you've created your own callback function and callback executor, 1:40
    and used two styles of anonymous functions. 1:44
    So far, the example we have used is pretty contrived. 1:47
    In the next few sections, we're going to take a look at some real world examples 1:51
    using timers and a document object model. 1:55

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