Check for a rapid return if the function ends up returning null in JavaScript

Question

Check for a rapid return if the function ends up returning null in JavaScript

Is there a way to make this code more concise?

const result = getResult();
if (!result) {
    return;
}

// Work with result

I have several instances of this code in my project and I'm looking for a simpler solution like:

const result = getResult() || return;

// Work with result

EDIT: I only want to persist inputs that can be converted.

const parseInput = (input: string): void => {
   const convertedInput = convert(input);
   if (!convertedInput) {
       return;
   }

   persist(convertedInput);
}

I am aware that I could call the converter twice, but I want to avoid that:

const parseInput = (input: string): void => {
   if (!convert(input)) {
       return;
   }

   persist(convert(input));
}

javascript typescript ecmascript-6

Answer 1

Answer №1

While your solution is solid, there's a fun twist you can add by experimenting with the functional style. One interesting technique is to wrap the value in a "monad," which will only trigger attached functions if the value is non-zero. Check out this playful implementation:

function possibly(x) {
    return {
        value: x,
        execute(fn) {
            if (this.value)
                this.value = fn(this.value)
            return this;
        }
    }
}

Using this possibly function, your code snippet could be reimagined as follows:

const processInput = input => possibly(transform(input)).execute(store)

For a more comprehensive approach, I recommend checking out Samantha's response.

Answer 2

While your solution is solid, there's a fun twist you can add by experimenting with the functional style. One interesting technique is to wrap the value in a "monad," which will only trigger attached functions if the value is non-zero. Check out this playful implementation:

function possibly(x) {
    return {
        value: x,
        execute(fn) {
            if (this.value)
                this.value = fn(this.value)
            return this;
        }
    }
}

Using this possibly function, your code snippet could be reimagined as follows:

const processInput = input => possibly(transform(input)).execute(store)

For a more comprehensive approach, I recommend checking out Samantha's response.

Answer 3

Answer №2

You have the ability to achieve this task

const finalResult =  "default value" || calculateResult();

If the function calculateResult returns null or is not defined, then the output will be finalResult as "default value". If that's your desired outcome

function calculateResult() {
   return null;
}
const finalResult =  "okay" || calculateResult();
console.log(finalResult)

And in case calculateResult is not provided, you will receive

const finalResult =  "okay" || calculateResult();
console.log(finalResult)

Essentially, the logic follows this pattern

null || undefined || null || 0 || "okay" || "defined" // "okay"

It follows a left-to-right evaluation, selecting the most relevant value

Answer 4

You have the ability to achieve this task

const finalResult =  "default value" || calculateResult();

If the function calculateResult returns null or is not defined, then the output will be finalResult as "default value". If that's your desired outcome

function calculateResult() {
   return null;
}
const finalResult =  "okay" || calculateResult();
console.log(finalResult)

And in case calculateResult is not provided, you will receive

const finalResult =  "okay" || calculateResult();
console.log(finalResult)

Essentially, the logic follows this pattern

null || undefined || null || 0 || "okay" || "defined" // "okay"

It follows a left-to-right evaluation, selecting the most relevant value

Answer 5

Answer №3

It's difficult to say whether this answer will meet your expectations, but it proposes a potential solution for handling unknown results.

Maybes are data structures that come with this type of verification already included. The .map() function below will only execute if there is a value in the Maybe, eliminating the need for manual value checks in the consuming code.

However, adapting to this approach requires a change in how you manage these values and typically involves using a library unless you create your own implementation. While not perfect, it does provide an alternative worth considering.

const { None, Some } = Monet;

const getResult = () => Math.random() > 0.5
? None()
: Some(1);

const test = getResult()
.map(x => x + 2);
  
console.dir(test.val);

<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="701615161d0c381606000b">[email protected]</a>/dist/monet.min.js"></script>

Answer 6

It's difficult to say whether this answer will meet your expectations, but it proposes a potential solution for handling unknown results.

Maybes are data structures that come with this type of verification already included. The .map() function below will only execute if there is a value in the Maybe, eliminating the need for manual value checks in the consuming code.

However, adapting to this approach requires a change in how you manage these values and typically involves using a library unless you create your own implementation. While not perfect, it does provide an alternative worth considering.

const { None, Some } = Monet;

const getResult = () => Math.random() > 0.5
? None()
: Some(1);

const test = getResult()
.map(x => x + 2);
  
console.dir(test.val);

<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="701615161d0c381606000b">[email protected]</a>/dist/monet.min.js"></script>

Check for a rapid return if the function ends up returning null in JavaScript

Answer №1

Answer №2

Answer №3

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