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Explain Empty Returns Like I'm Five

chrisvasqm profile image Christian Vasquez ・1 min read

This kind of code can be confusing for beginners when they start coding:

function doSomething() {
    if (somethingElseHappens())
        return;

    // ...
}
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How would you explain this in a real life scenario that could tell how/why this is useful?

Discussion (17)

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dance2die profile image
Sung M. Kim

You decided to go shopping for a gift(doSomething).
As you arrived at a train station, you got a push notification that all trains are canceled due to hurricane (somethingElseHappens()).
So you returned home without any gifts (return).
Or else you could've waited for hours for a train that will never show up.

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jerodsanto profile image
Jerod Santo

That was a super useful push notification! ✨

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dance2die profile image
Sung M. Kim

I should've used FEMA Alert as an example 😄

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thejoezack profile image
Joe Zack

Great example!

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stevenbruno profile image
Steven Bruno

Woah, I listen to your podcast all the time - never thought I'd see your name pop up in the wild!

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dance2die profile image
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theredspy15 profile image
Hunter Drum

Its commonly useful for when you need to end the function rather than return anything from the function.

In other words: functions don't always need to return a value to be useful, that can also perform tasks like printing a bunch of "Hello Worlds" to the screen. Whenever we return in a function, it stops executing that function (unless called again) at that exact line. It doesn't need a value to do this (technically it does, as blank is void & void is a value).

In short: the return statement isn't so much a "return" statement, as it is a statement that ends the function, and "returns" a value if there is one associated with it.

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chrisvasqm profile image
Christian Vasquez Author • Edited

Hey RedSpy,

Thanks for taking your time to comment. But the #explainlikeimfive hashtag is intended to be sort of like a "challenge" that involves explaining concepts with day to day situations so that an actual 5 year old can understand.

This may make things harder for those who reply but I've seen some really creative ideas here and there.

You can take these as example from Explain Dependency Injection Like I'm Five

Traditional: Picking what to wear when you get up in the morning.

Dependency Injection: Asking a pants, t-shirt and an hat from a stylist, and he makes sure you look lit AF.

"Dependency Injection" is a fancy way of saying that you have to ask someone else, like Mummy or Daddy, to give you anything you want to play with. You can't make the toy yourself, you need Mummy and Daddy to get it for you.

Sometimes, you don't know what toy you are going to get, like on your birthday, but all you need to know is that it will be a fun toy you can play with when you open the present.

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isaacdlyman profile image
Isaac Lyman • Edited

If I may add my two cents: all kinds of explanations are welcome on #explainlikeimfive. If we take the hashtag literally, we can't really get to the heart of a lot of technical topics. I mean, when I was five I was still potty training (sad, I know). I think simple--but perhaps not five-year-old simple--explanations are super valuable and this is a great place for them.

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chrisvasqm profile image
Christian Vasquez Author

Hey Isaac,

Yeah, you are right. I apologize if the way I expressed myself sounded like it was a mandatory way of doing it.

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theredspy15 profile image
Hunter Drum • Edited

Yah, I thought about that afterwards. If you would like me to remove the reply, I will

I did make sure it was simple enough that at least a 6 year old could understand (had to make this pun, sorry)

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chrisvasqm profile image
Christian Vasquez Author

Hahaha, don't worry 😂. Feel free to add the new one.

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owencrabtree profile image
Owen Crabtree

Its like when you go to the kitchen for cookies but there are no cookies so you return with nothing

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cjbrooks12 profile image
Casey Brooks

It's really nice in validation functions, where certain conditions must be met before proceeding. By returning early (maybe with a log about why), you keep the validation logic entirely flat. The alternative is making a deeply nested set of checks that are even more difficult to understand, since deep nesting makes it more difficult to know which lines of code are related

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icetruckcol profile image
IceTruckCol

Some functions are designed to return a value while others have a job to do that doesn't require anything to be returned. Return means exit the function either way but, if the design of the function expects a value to be returned, it must follow return like return 23;

When you start coding, you usually put returns at the end of functions after the work has been done. But after a while returns are placed inside ifs and loops and you usually end up coding multiple returns depending on the state of the application.

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cathodion profile image
Dustin King

I'd add more to the function:

function doSomething() {
    if (somethingElseHappens())
        return;

    stuff_i_dont_want_to_happen_if_somethingElseHappens_returned_true();
}

Example:

function doCookieCheck() {
    if(cookiesAreAuthorized()){
        return;
    }

    popUpAnnoyingCookieAuthorizationBanner();
}