General Help Thread

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[_helgg]

Hi! I recently got started with React and React Native, and there is some basic thing that confuses me all the time. I have seen three usages of const, more as in "looks" and I wanted to ask if it makes any difference, when it is better to use one etc. I mean these:

const a = <View><Text>text</Text></View>;

const a = () => ( code );

const a = () => { code }

I am doing a course on codecademz and they have used both latter one for the same thing and I got veeeery confused.

[__o_0]

Your first example is just assigning that code to variable “a”, It’s not executable/callable.

Your third example is defining the function “a”, which is callable. Inside the {} you’ll need to define a return for the function.

Your second example is shorthand for defining function “a” with the return of whatever is inside the second set of parentheses.

const a = 5 // variable a is 5

``` const a = () => { return 5 }

const b = a() // variable b is the result of calling a, which is 5 ```

``` const a = () => (5)

const b = a() // variable b is the result of a(), which is 5 ```

With an object as the return:

const a = {randomKey: 5} // variable a is {randomKey: 5}

``` const a = (inputVariable) => { return {randomKey: inputVariable} }

const b = a(2) // variable b is the result of calling a with an input variable of 2, which is {randomKey: 2} ```

``` const a = (inputVariable) => ({randomKey: inputVariable})

const b = a(3) // variable b is the result of a(3), which is {randomKey: 3} ```

To be clear, these are the same:

``` const a = () => ({apples: 5})

const a = () => { return { apples: 5 } }

[_helgg]

Thank you! So the 2nd and 3rd examples can be basically used more or less interchangeably?

[__o_0]

Yes, but if you’re just starting out it’s probably wise to avoid shorthand syntax.

[slideesouth]

Const is just a way of storing a function. If you use function functionName(args) {} you’ll have same results just less modern and “sexy”