Hm, playing devil's advocate, I think it is because the minus has not been defined as a string operation (e.g. it could pop the last char), so it defaults to the mathematical operation and converts both inputs into ints.

The first is assumed to be a concat because one of the parcels is a string...

It's just doing a lot of stuff for you that it shouldn't be in first place 🤭

From all the Javascript quiks this is the least stupid and the most obvious.

pro tip:

"ba" + 0/0 + "a"

The risk is when it happens unintentionally. The language is bad for hiding such errors by being overly 'helpful' in assuming intent.

The problem is consistency.

JS should have never leaved the Browser side. Now you can use this thing for Backend and is just awful

so plus coerces into string if not number, was that so hard?

Instead of trying to make it work, javascript could just say "error." Being untyped doesn't mean you can't have error messages.

https://en.wikipedia.org/wiki/Stockholm_syndrome

It does to some degree.

• "11" is string, 1 is an int, because strings can be added (+) convert int to string and combine: "11"+"1" = "111"
• "11" is string, 1 is an int, because strings cant be subtracted (-) convert string to int and combine: 11-1 = 10

I'm not into JS so I don't know how it takes priority. ints can be added too, so I guess its basing it on the first variable which is compatible with the operator: in the first case string, in the second case int.

If this is how it works, it makes sense. But imo its a case of the designers being preoccupied with whether or not they could, they didn't stop to think if they should.

.... It does?

the programming language that had a stated design goal to do its best and try to keep running scripts that make no sense...

...itself makes no sense. It is wrong and bad that Javascript was ever designed that way in the first place.

BS. A language shouldn't have operators that allow non sensical operations like string concatenation when one operand is not a string.