As logically concluded by the linq example: None is the same as !Any, so you could define your own utility method like this:

const none = (arr, callback) => !arr.some(callback)

And then call like this:

const arr = ["a","b","c"]
const hasNoCs = none(arr, el => el === "c") // false
const hasNoDs = none(arr, el => el === "d") // true

Demo in Stack Snippets

const none = (arr, callback) => !arr.some(callback)

const arr = ["a","b","c"]

const hasNoCs = none(arr, el => el === "c") // false
const hasNoDs = none(arr, el => el === "d") // true

console.log({hasNoCs, hasNoDs})

Do:

opposite_index = arr.length - index - 1

For example:

a = [1,2,3,4,5,6,7,8,9,10]

index = 3
a[index]
4

It's opposite is 7 so:

opposite_index = a.length - index - 1
a[opposite_index]
7

With reverse as per @Maheer Ali suggestion:

a.reverse()[index]
7