Javascript rest parameters

Question

function containsAll(arr) {
for (let k = 1; k < arguments.length; k++) {
let num = arguments[k];
if (arr.indexOf(num) === -1) {
return false;
}
}
return true;
}
let x = [2, 4, 6, 7];
console.log(containsAll(x, 2, 4, 7));//true
console.log(containsAll(x, 6, 4, 9));//false

why does first array becomes true while the other one is false since they have the nmber arguements?

Answer 1

The function searches all numbes in the array.
In the first statement all numbers are found, and true is returned.
In the second statement the 9 is not found in the array, so false is returned.

Answer 2

so why did the x is in within the ()

Answer 3

Its a parameter for the function.
Its assignt to arr.
The other argumeters are accessed via the arguments array.

Answer 4

oh thank you very much