Why is includes in JavaScript case sensitive?-CodePudding

I recently stumbled upon a bug caused by .includes() method in javascript. I wanted to return the exact result in respect to case-insensitive but for some reason this does not works

["Ford", "BMW", "Fiat"].includes("bmw");
//returns false
//expected result true

I then fixed my issue with the help of .find() like below:

!!["Ford", "BMW", "Fiat"].find(el => el.toUpperCase() === "bmw".toUpperCase());
//returns true

Can someone help me understand why includes does not work in case-insensitive situations ?

CodePudding user response：

Why would it work case-insensitively? Quoth the MDN:

The includes() method determines whether an array includes a certain value among its entries, returning true or false as appropriate. [...] Note: Technically speaking, includes() uses the sameValueZero algorithm to determine whether the given element is found.

sameValueZero is defined to be Object.is but with 0 and -0 being equal.

That being the case, we can try that out:

> Object.is("bmw", "BMW")
false
> Object.is("bmw", "bmw")
true