hello again. This is Kyle. Today we're going to be talking about semicolons. So, if you've been watching my videos, you may have noticed something missing. Where are my semicolons? Now, you may or may not know that in JavaScript, semicolons are optional. Basically, if you omit them, such as we do there, it works. We can put a semicolon here, but if we omit them, JavaScript will automatically insert one for us. This is called automatic semicolon insertion. So, they're perfectly optional to put one here. So, if we do console.log works, spell it right, and don't have any semicolons, it works. Maybe I just want one semicolon. That still works. Or if I want to put semicolons at the end of each line, that still works. I can go crazy, and I could put semicolons in the beginning of my lines. That still works. Another one is maybe I want three semicolons at the end of my line, just, you know, for that extra safety to ensure that nothing, that my code doesn't break.

that still works too. Now, some of you are probably thinking, No semicolons, that's bad code, you're a bad person, and you're sort of correct. Let's take out these semicolons here. There are a few instances in which, if you omit semicolons, you can run into some trouble, such as if you just declare an array here, so to say one, two, three, and we'll say for each, and we just want to print out each of these numbers here. I'm going to say this. Uh-oh, cannot read property three of undefined. What is that? If only I had put a semicolon here, it would have worked. Another example is if I have a function that calls itself or a immediately invoked function. Console.log gir and save this. Console.log is not a function. Of course, it's a function. It's a... I forgot my semicolon. I put my semicolon back. It works. So, and then there's another really weird instance too. If you say, if you have a return statement here, and then you put the return on a new line, I don't

know bear equals 1. This will be evaluated like such and not what you expect at all because they'll be returning null and not the bear you want. But I mean really, who does that? I don't know, don't do that, I don't know. But anyways, these three instances are the main problem of people who don't use semicolons and why people say it's bad. Now, I've been writing JavaScript for many, many years, and personally, I've never once ran into an issue where I said, Oh man, if only I used a semicolon. Now, what I tend to do is with arrays, I will actually give them a variable name because there's very few times I'm just going to an it on an array and want to loop through right after it's an it. And usually want to be assigned to a variable. And with immediately invoked ins function expressions, you know, go ahead, Adam, medic semicolon there. It's not like if you don't use semicolons, you're forbidden to use them everywhere or another way is

just you know give that function a proper name and then call it so you don't need it's not you know it's not fancy JavaScript but it's it works you know so the reason why I don't use semicolons when I'm teaching JavaScript is because I find it helps avoid some of the confusion and some of the guessing with people especially new to the language so like for instance let's take an example if I write a function bear here at the end here do I put a semicolon and the answer is no because this is just a function we don't need a semicolon here it's it's not you shouldn't put a semicolon there but if instead I wrote the bear function as an expression like this then you should put it a semicolon there at the end of line that is the proper way ah now let's let's move on to other statements such as if is bear do I put a semicolon here nope no semicolon there same thing with other loops still a bear.

We wouldn't want to put a semicolon here either, so that can be kind of confusing as a new person, of which lines, which curly braces do we end with semicolons. Some another example is, so say we here we have lit up the double that I can't speak. We have a function bear here that returns an object, and this object is just the type of bear grizzly. And so, you know, where do we put the semicolons here? Do we put one here? Nope, doesn't go there. Should we put one here? Yes, you should put a semicolon there. And then, you know, even with es6, say we have a class pair that has a growl function on it that returns a growl. Should we put a semicolon here? Yep, semicolon goes there. What about here? Nope, no semicolon there. And no semicolon here. So, it just gets confusing to new people, especially of where a semicolon should go and where a semicolon shouldn't go. And so, my theory on this is the amount of decisions you need to make.

while coding, while writing in my cones will be greater than without semicolons. So, for instance, just the more decisions you make while coding, the quicker you'll fatigue by coding. But I don't know, maybe that's really dumb, and I'm just a bad person. I just want you to know that I purposely don't use semicolons because I truly do care about you learning JavaScript in the least confusing way that I know. So now I have a challenge for you. If you've been writing JavaScript and you've never ever used semicolons, I encourage you to spend a month and write JavaScript with semicolons just to get a feel of how it is and how the other side lives. And if you have always written your JavaScript using semicolons, I want you to write your JavaScript for an entire month using two semicolons. That will give you a feeling of what people who don't like semicolons, how they feel about semicolons by writing the extra one there. Anyways, thanks for listening to my rant. Please

write a comment below on your thoughts about semicolons, and even if you think I'm a horrible person for writing this bad code without semicolons, please let me know. Thanks again for watching.

Are Semicolons Necessary in JavaScript?

Are Semicolons Necessary in JavaScript?

스크립트