2.5 fleche function

Hello everyone, I hope you are doing well. Welcome to this new video where we’re going This is a different syntax for the creation of Javascript functions. A normal javascript function looks like of course to this.

You can also note a syntax where you have var myFunc equal to function. Now, an arrow function looks like this. Here, I store it in a constant and then right side of the equal sign. This is the syntax of the arrow function. A list of arguments is nothing, but it can contain 0:35 arguments, and then an arrow. So, an equal sign and a sign greater than, and then the body of function.

The snyntax arrow of the function is a bit shorter than the normal syntax because she omits the function keyword and this is also a considerable advantage. Solves many problems that you have often met with the. If you worked a little with javascript, you probably know that the keyword THIS does not always refer to WHAT you could have you wait for when writing your code. When you use this function in a arrow, it will always keep its context and will not change it not at run time. Now let’s move to jsbin Let’s create a normal function, printMyName like this. Now, here we can of course display the name of the console log output and name of passes as an argument.

Now let’s write printMyName and in it we will put our first name Matthew . We have Matthew. Now the equivalent of the arrow function is the store as a constant named printMyName. It could also be created with let. If you plan to reassign this printMyName variable as a constant. And now, don’t forget to add this arrow between the list of arguments and the body of the function. If you delete and rerun this operation, you’ll always see Matthew. So here he behaves in exactly the same way. Now, the keyword-thing is something you will see throughout the course. This becomes important once you have added object functions, of course. First of all, let me show you some alternatives to this syntax, regarding the list of arguments. To be precise. If you do not receive only one argument, like this If you receive only one argument as we do here, you can also Use a shortcut to omit parentheses. This is only valid for exactly one argument, not for more and not for less.

Here you will always get the same result. If you had a function that does not receives no argument. You need to You also need brackets. So, name and age like that won’t work. You’ll have to wrap this in parentheses. And now you can write name and age and pass both as arguments here. So these are two different syntaxes that you might see regarding arguments. There is also an alternative. So on the right side of the arrow. Obviously, a lot of functions return something. So let’s say here that we really want to multiply some thing and that we get a number as argument. We now want to return the number * 2.

Of course, what we can do, it’s that we can record the result of the multiplication. Therefore, what is returned by multiply and pass two here. If now I delete this and throw it, we should see four if you have this case where everything you do in the body of your function is returned and that you have no other code, you can omit the braces, write it on a line and the keyword return as well. It is a very short version of writing this function. It gets a little shorter if we take advantage the shortcut to delete the parentheses surrounding the single argument. And now it always returns the result of this code. Here, we omit just the keyword back and we have omitted two. And we have a very concise and short way of writing a function that takes one or several arguments and flip something.

So, here, delete and execute this still gives 4. So it’s all the syntax that you can see and the function arrow in general is something you will often see. You have seen the different syntaxes. You are not required to remember everyone now. Just know that there are different syntaxes and that if we use them afterwards, they will come back to you quickly and you will know why we use a given syntax. thank you for watching we meet on the next course