How can I create multi columns from a single unordered list?

Question

I'd like to create a multi column list like this: https://jsfiddle.net/37dfwf4u/

No problem when using a different list for each column:

<ul>
    <li>item1</li>
    <li>item2</li>
    <li>item3</li>
    <li>item4</li>
</ul>
<ul>
    <li>item5</li>
    <li>item6</li>
    <li>item7</li>
    <li>item8</li>
</ul>

ul {
    display:inline-block;
}

However, can this be done by a continuous list and pure CSS so that the CSS arranges the columns automatically? E.g. by use of flex layout which I'm not yet familiar with?

Answer 1

Yes, you can create a multi column list as described if you make the ul a flex container, change the flex-direction to column, allow it to wrap by applying flex-wrap: wrap and additionally force it to wrap by limiting its height:

ul {
  height: 100px;
  display: flex;
  flex-direction: column;
  flex-wrap: wrap;
}

<ul>
  <li>item1</li>
  <li>item2</li>
  <li>item3</li>
  <li>item4</li>
  <li>item5</li>
  <li>item6</li>
  <li>item7</li>
  <li>item8</li>
  <li>item1</li>
  <li>item2</li>
  <li>item3</li>
  <li>item4</li>
  <li>item5</li>
  <li>item6</li>
  <li>item7</li>
  <li>item8</li>
  <li>item4</li>
  <li>item5</li>
  <li>item6</li>
  <li>item7</li>
  <li>item8</li>
</ul>

Answer 2

Consider using CSS3 Multi-column Layout for that:

CSS3 Multiple Columns

You can do that using just one list and define the number of columns with CSS. If you check CSS3 Multi-column layout browser support here you can see partial support by most of the browsers, because they do not support break-before, break-after and break-inside properties. But they do support the properties you will need to create a multi column list with a prefix.

.container {
  -webkit-column-count: 2; /* Chrome, Safari, Opera */
  -moz-column-count: 2; /* Firefox */
  column-count: 2;
}

ul {
  margin: 0;
}

<div class="container">
  <ul>
    <li>item1</li>
    <li>item2</li>
    <li>item3</li>
    <li>item4</li>
    <li>item5</li>
    <li>item6</li>
    <li>item7</li>
    <li>item8</li>
  </ul>
</div>