Javascript验证允许最多3个逗号和1个逗号中的20个字符？

Question

Javascript验证允许最多3个逗号和1个逗号中的20个字符？

$('#txt_tags').keyup(function () {
    var tags = $(this).val().split(',');

    if (tags.length > 13)
        alert('there is more than 13 tags');
});

Answer 1

您只需迭代标记数组并检查它们的长度。

$('#txt_tags').keyup(function () {
    var tags = $(this).val().split(',');

    if (tags.length > 13)
        alert('there is more than 13 tags');

    tags.forEach(function(tag){
       if(tag.length > 20)
         alert("Tag has more than 20 characters");
    });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" id="txt_tags" />

Answer 2

试试这个：

$('#txt_tags').keyup(function () {
    if($(this).val().match(/^([^,]*,){14,}|([^,]{21,})/g))
        alert("NOT VALID!");
});

([^,]*,) --> match every comma separated by every char except comma
{14,} --> match it 14 or more time
| --> or
[^,] --> every char except comma
{21,} --> match it 21 or more time