Question

我想在我的文本框中限制最多两个数字。但是当一个点（即一个点）出现时，限制必须释放，并且在该点之后它可以扩展到4。

即如果我尝试键入100，则启用限制并限制仅键入最多10个。但如果我键入10.303启用我...

我是jquery的新手。我尝试了很多方法，但它不会起作用。任何帮助都会非常值得关注

Answer 1

下面是

的解决方案：

$(function () {
    $(".txt").on("keyup", function(event) {
        // don't handle backspace, delete, pgup/pgdn, home/end, or arrow keys:
        if (event.keyCode === 8 || event.keyCode === 46 || event.keyCode >= 33 && event.keyCode <= 40) return false;

        var currentEl = $(this);
        var value = $(currentEl).val();

        // remove letters...
        value = value.replace(/[^0-9.-]/g, "");

        var hasDecPlace = value.match(/\./);

        // separate integer from decimal places:
        var pieces = value.split('.');
        var integer = pieces[0].replace('-', '');
        var decPlaces = ""
        if (pieces.length > 1)
        {
            pieces.shift();
            decPlaces = pieces.join('').replace('-', '');
        }

        // handle numbers greater than 99.9999... :
    if (integer > 99.9999 || integer === 99.9999 && parseInt(decPlaces) > 0)
        {
            integer = "99";
            decPlaces = getZeroedDecPlaces(decPlaces);
            alert("number must be between 0 and 99");
        } // ...and less than 0:
        else if (parseInt(integer) < 0)
        {
            integer = "0";
            decPlaces = getZeroedDecPlaces(decPlaces);
            alert("number must be between 0 and 99");
        }



// handle more than four decimal places:
        if (decPlaces.length > 4)
        {
            decPlaces = decPlaces.substr(0, 4);
            alert("number cannot have more than four decimal places");
        } 


        var newVal = hasDecPlace ? integer + '.' + decPlaces : integer;

        $(currentEl).val(newVal);
    });

    function getZeroedDecPlaces(decPlaces) {
        if (decPlaces === '') return '';
        else if (decPlaces.length === 1) return '0';
        else if (decPlaces.length >= 2) return '00';
    }
});

如何使用jquery限制文本字段中的数字

1 个答案: