仅允许字母数字值 [英] Allowing only Alphanumeric values

问题描述

可能重复:
如何防止用户输入无效字符在输入字段中

Possible Duplicate:
How to prevent users from entering invalid characters inside an input field

我在页面上有3个文本框.其中一个应该允许数字，其他字母和第三个字母可以是数字或字母.

I have 3 textboxes on a page. One of them should allows numbers, the other alphabets and the 3rd either numbers or alphabets.

因为这是唯一的要求，所以我不想使用验证插件或任何其他第三方插件.如何通过使用纯jQuery创建自己的插件来做到这一点?

Since this is the only requirement, I do not want to use the validation plugin, or any other 3rd party plugin. How can I do this by creating my own plugin using pure jQuery?

这是我所做的，但是我感觉代码太长了

This is what I have done but I get a feeling that the code will become too long

 $(this).keydown(function(e)
        {
            var key = e.charCode || e.keyCode || 0;            
            return (
                key == 8 || 
                key == 9 ||
                key == 46 ||
                (key >= 37 && key <= 40) ||
                (key >= 48 && key <= 57) ||
                (key >= 96 && key <= 105));
        });

http://jsfiddle.net/Cvus8/

谁能告诉我哪种方法是解决此问题的最佳方法?

Can anyone tell me which si the best way to approach this issue?

推荐答案

更好的解决方案可能是使用基于正则表达式的检查.下面的示例将在ID为text的字段中仅限制字母数字字符:

The better solution might be to go with regular expression based checks. Example below will limit only alphanumeric characters in the field with id text:

$('#text').keypress(function (e) {
    var regex = new RegExp("^[a-zA-Z0-9]+$");
    var str = String.fromCharCode(!e.charCode ? e.which : e.charCode);
    if (regex.test(str)) {
        return true;
    }

    e.preventDefault();
    return false;
});

这篇关于仅允许字母数字值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！