input填写银行卡号，每四位空一隔

jquery

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<input type="text" id="J_BankCard"/>
<script src="http://static.dtao.org/libs/jquery/1.11.2/jquery.js"></script>
<script>
    !function () {
        $('#J_BankCard').on('keyup mouseout input',function(){
            var $this = $(this),
                v = $this.val();
            /S{5}/.test(v) && $this.val(v.replace(/s/g,'').replace(/(.{4})/g, "$1 "));
        });
    }();
</script>
</body>
</html>

原生

!function () {
    document.getElementById('bankCard').onkeyup = function (event) {
        var v = this.value;
        if(/S{5}/.test(v)){
            this.value = v.replace(/s/g, '').replace(/(.{4})/g, "$1 ");
        }
    };
}();

转自：http://www.dtao.org/archives/472