input 글자수 입력 후 다음 칸에 focus

input maxlength 값 만큼 입력 후 다음 input에 자동으로 focusing 된다.

카드번호 입력, 비밀번호 1글자씩 입력 등에 사용된다.

<form class="">
    <div class="form__group">
        <div class="form__item">
            <label>카드번호</label>
            <div class="form__item-input flex">
                <div class="form__item-hasbtn w20">
                    <input type="text" class="wfull section__joincard_1" pattern="[0-9]*" inputmode="numeric" placeholder="입력해주세요" autocomplete="off" maxlength="4">
                    <a href="#" class="clear-text inp-del">취소</a>
                </div>
                <div class="form__item-hasbtn w20">
                    <input type="text" class="wfull section__joincard_2" pattern="[0-9]*" inputmode="numeric" placeholder="입력해주세요" autocomplete="off" maxlength="4">
                    <a href="#" class="clear-text inp-del">취소</a>
                </div>
                <div class="form__item-hasbtn w20">
                    <input type="text" class="wfull section__joincard_3" pattern="[0-9]*" inputmode="numeric" placeholder="입력해주세요" autocomplete="off" maxlength="4">
                    <a href="#" class="clear-text inp-del">취소</a>
                </div>
                <div class="form__item-hasbtn w20">
                    <input type="text" class="wfull section__joincard_4" pattern="[0-9]*" inputmode="numeric" placeholder="입력해주세요" autocomplete="off" maxlength="4">
                    <a href="#" class="clear-text inp-del">취소</a>
                </div>
            </div>
        </div>
        <div class="form__item">
            <label>유효기간</label>
            <div class="form__item-input">
                <div class="form__item-hasbtn">
                    <input type="text" class="wfull section__joincard_5" placeholder="입력해주세요" autocomplete="off">
                    <a href="#" class="clear-text inp-del">취소</a>
                </div>
            </div>
        </div>
    </div>
</form>

$(".section__joincard .form__item-input.flex input").keyup (function () {
    var charLimit = $(this).attr("maxlength");
    if (this.value.length >= charLimit) {
        $(this).parent().next().find('input').focus();
        return false;
    }
});