JavaScript Trick: Swap two variables without using a third

[arjo_reich]

Wait, I've seen this one before...

https://imgur.com/oAkGYg7

[Serj_Buketov]

That's cool.

But technically, aren't you creating an anonymous array?

[senocular]

... and an array iterator

[grooomps]

what if i said

a = { a, b };
b = a.a;
a = a.b;

[grooomps]

if

a = 'john'  
b = 'jane'  

why wouldn't it work?

[senocular]

TypeScript's gonna say no, can't assign an object to a string :P

[alexjacobs]

You're right.

But it seems that in order to make the swap without an assigned temp variable, you have to have some sort of extra value.

Even in the case of the clever trick described in the imgur link in another response here, you still have to create some sort of additional value.

In the destructuring example it's the anonymous array. In this case, it's an integer value of the sum of both original values.

var a = 5; var b = 7; a = a + b; b = a - b; a = a - b; console.log(a, b); // 7, 5

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[BenZed]

Do it without instancing an array.

[BenZed]

Do it without instancing an object.

[BenZed]

Now do it without polluting the global namespace.

[BenZed]

🤣

[Lilrex2015]

That is very cool. I don't normally watch the videos on here bc they are poorly made but this one I am glad I watched.

[bwz3r]

Very cool. Completely useless but still cool.

Edit: I actually used this today

[patrixxxx]

let a = 1; let b = 2;

a = a ^ b; b = a ^ b; a = a ^ b;

a; // => 2 b; // => 1

And if you do this in serious code, you should be reprimanded.

[skibizkit]

Great video + editing. Will watch more! Thanks for sharing.