CODEWITHSUNDEEP
javascript
Arijit Shome
Arijit Shome

Reputation: 23

Clarification required in Javascript coercion example

var a = 1+1+'2';
console.log(a);
> 22

var a = 1+1+'2'+7;
console.log(a);
> 227

var a = 1+1+'2'+7+10;
console.log(a);
> 22710

var a = 1+1+'2'+7+10-2;
console.log(a);
> 22708

where is the 0 coming from in 22708? coercion example.

Upvotes: 2

Views: 38

Answers (2)

M Kemp
M Kemp

Reputation: 66

Javascript handles the subtract and minus signs differently. You get the zero because it is taking 22710 and subtracting 2 to get 22708.

So it goes from 2 To 22 To 227 To 22710 To 22710 - 2 Which gives 22708

The actual reason as to why is way over my head though.

Upvotes: 0

Amadan
Amadan

Reputation: 198388

The hint is in the previous evaluation. 1+1+'2'+7+10-2 is equivalent to ((1+1)+'2'+7+10)-2, or "22710"-2. While + is defined for both strings and numbers (it's addition when both arguments are numbers, concatenation in any other case), - is only defined for numbers; and so "22710" is coerced to number: 22710-2 is indeed 22708.

Upvotes: 3

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