const compareString = (a, b) => {

        if (a === null && b !== null) {

            return 1;

        } else if (a !== null && b === null) {

            return -1;

        } else if (a !== null && b !== null) {

            return a.toLowerCase() > b.toLowerCase() ? 1 : a.toLowerCase() === b.toLowerCase() ? 0 : -1;

        } else {

            return 0;

        }

};

​

const compareString2 = (a, b) => {

        const s1 = a ? [...a.toLowerCase()].reduce((prev, char) => prev + char.charCodeAt(0), 0) : 0;

        const s2 = b ? [...b.toLowerCase()].reduce((prev, char) => prev + char.charCodeAt(0), 0) : 0;

​

        return a && b ? Math.sign(s1 - s2) : Math.sign(s2 - s1);

};

​