html实现input只允许输入数字的三种方法

html实现input只允许输入数字的三种方法

方法一：判断键盘的keyCode

代码如下：

$(document).ready(function() {
    $(\"#txtboxToFilter\").keydown(function (e) {
        // Allow: backspace, delete, tab, escape, enter and .
        if ($.inArray(e.keyCode, [46, 8, 9, 27, 13, 110, 190]) !== -1 ||
             // Allow: Ctrl+A, Command+A
            (e.keyCode === 65 && (e.ctrlKey === true || e. Key === true)) || 
             // Allow: home, end, left, right, down, up
            (e.keyCode >= 35 && e.keyCode <= 40)) {
                 // let it happen, don\'t do anything
                 return;
        }
        // Ensure that it is a number and stop the keypress
        if ((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) {
            e.preventDefault();
        }
    });
});

第二种方法：正则表达式

$(\'input[name=\"number\"]\').keyup(function(e) {
    var float = parseFloat($(this).attr(\'data-float\'));

    /* 2 regexp for validating integer and float inputs *****
        > integer_regexp : allow numbers, but do not allow leading zeros
        > float_regexp : allow numbers + only one dot sign (and only in the middle of the string), but do not allow leading zeros in the integer part
    *************************************************************************/
    var integer_regexp = (/[^0-9]|^0+(?!$)/g);
    var float_regexp = (/[^0-9\\.]|^\\.+(?!$)|^0+(?=[0-9]+)|\\.(?=\\.|.+\\.)/g);

    var regexp = (float % 1 === 0) ? integer_regexp : float_regexp;
    if (regexp.test(this.value)) {
        this.value = this.value.replace(regexp, \'\');
    }
});

第三种方法：使用html5 type="number"

<input type=\"number\" name=\"quantity\" min=\"0\" max=\"9\">