The includes() method determines whether an array includes a certain value among its entries, returning true or false as appropriate.
Syntax:
arr.includes(valueToFind[, fromIndex])
const arr = [10, 20, NaN, 30, 40, 50];
arr.includes(20); //true
arr.includes(60); //false
arr.includes(20, 3); //false
arr.includes(10, -2); //false
arr.includes(40, -2); //true
arr.includes(NaN); //true If `fromIndex` is negative, the computed index is calculated to be used as a position in the array at which to begin searching for valueToFind. If the computed index is less or equal than `-1 * array.length`, the entire array will be searched.