Auto tab between N fields.

autotab.js

(function(){
    /**
     * Focus on the next input
     *
     * @param current
     * @param to
     * 
     * @see https://bartamediagroup.com/auto-tab-html-input-fields/
     */
    function tab(current,to){
        if (current.getAttribute && current.value.length == current.getAttribute("maxlength") && to.focus) {
            to.focus();
        }
    }

    /**
     * Auto tab between all the input fields passed as parameters.
     * All them MUST have maxlength property filled.
     *
     * Example:
     *
     * const input1 = document.getElementById('input1');
     * const input2 = document.getElementById('input2');
     * const input3 = document.getElementById('input3');
     * autotab(input1, input2, input3);
     *
     * @param inputs
     */
    window.autotab = function(inputs) {
        const l = arguments.length;

        for (let i = 0; i < l; i++) {
            if (i+1 < l) {
                const input = arguments[i];
                const dest = arguments[i + 1];

                input.addEventListener('input', function(){
                    tab(input, dest);
                });
            }
        }
    };
})();