Question

使用罗马数字假定以下html中的有序列表

<ol type="I">
    <li>one</li>
    <li>two</li>
    <li>three</li>
    <li>four</li>
    <li value="1984">big brother</li>
</ol>

哪个呈现为：

        I. one
       II. two
      III. three
       IV. four
MCMLXXXIV. big brother

在给定任意元素的情况下，是否有一种方法可以从其属性中提取用作该元素前缀的字符串？

例如，给定第四个元素，我可以做些什么来获取字符串IV吗？还是给定最后一个元素，得到字符串MCMLXXXIV？

Answer 1

您需要编写一个romanize函数。如果我正确理解您的问题。

将列表项的索引作为值或数据元素会有所帮助。

Here is a fiddle

$("li").each(function(){
    
    if ($(this).text() === 'big brother') {
    	alert(romanize($(this).val()));
    }
 });
 
 function romanize (num) {
    if (isNaN(num))
        return NaN;
    var digits = String(+num).split(""),
        key = ["","C","CC","CCC","CD","D","DC","DCC","DCCC","CM",
               "","X","XX","XXX","XL","L","LX","LXX","LXXX","XC",
               "","I","II","III","IV","V","VI","VII","VIII","IX"],
        roman = "",
        i = 3;
    while (i--)
        roman = (key[+digits.pop() + (i * 10)] || "") + roman;
    return Array(+digits.join("") + 1).join("M") + roman;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<ol type="I">
  <li value="1">one</li>
  <li value="2">two</li>
  <li value="3">three</li>
  <li value="4">four</li>
  <li value="1984">big brother</li>
</ol>

As seen here

获取HTML有序列表中元素的前缀

1 个答案: