JavaScript operators

In JavaScript "11" + 1 is 111,
but "11" - 1 gives 10
Can anyone please help me with this ?

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so after reading the entire thing on the link u did gave me
i could only figure out the next:

the “” makes the “11” a string
the + sign is an arithmetic operator
and u have a num
a num is true
a string is false

true true  = true so they added 1

arithmetic operators ( - + * / % ). Note, that binary + does not trigger numeric conversion, when any operand is a string.

then we have
again a string “11”
another - arithmetic operator but - is false
another num
Boolean(-0) // false
so it becomes
false + false = false the -1 is then substracted

How does it help the persone above excatly?

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It explains, in full, JavaScript’s type coercion rules. And in this case, implicit type coercion is the thing that applies.And the article explains this in detail.

If you don’t understand, or didn’t read that far:

In situations with an operator (eg a + b, c - d), JavaScript coerces types so that they are the same on both sides. So for

"11'" - 1
string - number

The types on both sides have to be a number, it makes no sense otherwise. So coerce string -> number. As long as it can convert to a number, that will work.

"11" + 1
string + number

The types here either have to both be string or both be number, because + is either addition or concatenation. With +, JS always tries to coerce to string, so "11" + "1" is “111”.


Javascript’s type system is basically insane. Don’t try to look for a ton of consistency in it.


Thank You so much guys for your response