An ES6 utility function for finding the nth-max value in an array

nthMax.js

/**
 * An ES6 utility function for finding the nth-max value in an array.
 */

let nthMax = (array, nth = 1) => {
    if(nth > (array.length - 1)) {
        throw new Error('Nth max value exceeds array size');
    }
    let newArr = array,
        i = 0;
        while(i < nth) {
            array.splice(newArr.indexOf(Math.max(...newArr)), 1);
            i++;
        }
        return Math.max(...newArr);
}