Function isString

tests/test_code/js/moment/moment.js:3616–3618

(input)

        subtract = createAdder(-1, 'subtract');

    function isString(input) {
        return typeof input === 'string' || input instanceof String;
    }

    // type MomentInput = Moment | Date | string | number | (number | string)[] | MomentInputObject | void; // null | undefined
    function isMomentInput(input) {