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What's the value of x?

Hey, devs from all over the world. 😊

let x = 0;

x++;
x = x++;
x = ++x;

console.log(x);
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What's the value of x? πŸ€”πŸ€”

Top comments (5)

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xtrp profile image
Gabriel Romualdo • Edited on

Placed before a variable, "++" adds one to the variable and the expression with "++" equals the new value of the variable + 1. This can be seen in line 4, where "x = ++x;" really means "x = (x + 1)".

Placed after a variable, however, "++" adds one to the variable and the expression with "++" equals the first value of the variable, without 1 added. This is why line 3, "x = x++;" has no effect β€” because the "x = x + 1" execution that the "++" gives is executed but then replaced by the the previous value of x.

In the end, you have:

let x = 0; // x = 0

x++; // x = x + 1 --> x = 1
x = x++; // x = x --> x = 1
x = ++x; // x = x + 1 --> x = 2

console.log(x); // 2

I hope my explanation made sense to you, was a bit hard to explain.

β€” Gabriel

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thinkdigitalsoftware profile image
ThinkDigitalSoftware • Edited on

3?
Dangit. I believe it would be 3 in dart

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bassemmohamed profile image
Bassem IbrahimπŸ‘¨β€πŸ’»πŸ‡ͺπŸ‡¬ Author

Well, I am not sure about dart. But we can try it out!!
In javascript its 2 for sure.

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TOD TheOtakuDev

2, for a simple reason explained here:
docs.w3cub.com/javascript/operator...

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