javascript - 限制html输入框内的字符串只能是状态缩写

Question

您好!

我正在编写一个新的 HTML 表单，该表单将收集更多元素的州缩写(即“ks”)。现在我有 -input field- limited 所以它只允许 2 个字符。这并不能阻止访问者在字段中随机输入一些东西，比如“SS”。

我想要一个代码，允许我将该字段中可以放置的内容限制为仅美国的官方州缩写。

到目前为止，我在我的网站上使用的是 HTML、CSS 和 Javascript。感谢您的所有帮助和想法!

Answer 1

更新。添加了所有状态、大写处理和 jsfiddle 链接。

这是一个纯 javascript 实现，应该让您了解您需要做什么:

<script>
    function validateState(el) {
    //put all states in this array. 
    var states =    ["AK","AL","AR","AS","AZ","CA","CO","CT","DC","DE",
"FL","GA","GU","HI","IA",
"ID","IL","IN","KS","KY","LA","MA","MD","ME","MH","MI","MN","MO","MS","MT",
"NC","ND","NE","NH","NJ","NM","NV","NY","OH","OK","OR","PA","PR","PW","RI",
"SC","SD","TN","TX","UT","VA","VI","VT","WA","WI","WV","WY"];
    for(var i=0;i< states.length;i++) {
      if(el.value.toUpperCase() == states[i]) {
        return true;
      }
    }
    //clear element if it doesn't match a state
    el.value = ""; //you could maybe do something else here.
    return false;
}
</script>
<input class="up" type="text" maxlength="2" onchange="validateState(this);"/>

在此处查看它的实时运行情况:http://jsfiddle.net/k7QQs/