html 限制textarea中的总行数和文本长度

Posted 2021-05-11

<textarea id="choices" limit="100,10"></textarea>
<span id="used-lines">0</span>

<script>
$(document).ready(function() {
    var limit = function (event) {
        var chars = $(this).attr("limit").split(",")[0];
        var lines = $(this).attr("limit").split(",")[1];
        var array = $(this).val().split("\n");

        $.each(array, function (i, value) {
            array[i] = value.slice(0, chars);
        });

        if (array.length >= lines) {
            array = array.slice(0, lines);
        }

        $(this).val(array.join("\n"))
        $('#used-lines').text(array.length);
    }

    $("#choices").keydown(limit).keyup(limit);
})
</script>