Understanding Display Properties: Flex and Inline-Flex

In CSS, the display property is used to define how an element is displayed. Two commonly used values for this property are flex and inline-flex. While they may seem similar, there is a key difference between them.

The main difference between display: flex and display: inline-flex lies in how the container element is displayed, not its children. When an element has display: flex, it behaves like a block-level element, taking up the full width available to it. On the other hand, when an element has display: inline-flex, it behaves like an inline-level element, only taking up the space needed for its content.

To illustrate this difference, consider the following example:

.flex-container {
  display: flex;
  background-color: #f0f0f0;
}

.inline-flex-container {
  display: inline-flex;
  background-color: #f0f0f0;
}

In this example, both containers have a flex layout for their children, but the .flex-container will take up the full width of its parent, while the .inline-flex-container will only take up the space needed for its content.

Another key aspect to understand is that the display property affects the outer display type of an element, which determines how it interacts with other elements in the document flow. The inner display type, on the other hand, determines how the children of an element are laid out.

The two-value syntax for the display property can help clarify this distinction:

display: block flex; /* equivalent to display: flex */
display: inline flex; /* equivalent to display: inline-flex */

In summary, when choosing between display: flex and display: inline-flex, consider how you want the container element to behave in relation to other elements on the page. If you want it to take up the full width available, use display: flex. If you want it to only take up the space needed for its content, use display: inline-flex.

Here’s an example that demonstrates the difference:

<div class="container">
  <div class="flex-container">Flex Container</div>
  <div class="inline-flex-container">Inline-Flex Container</div>
</div>

.container {
  width: 400px;
}

.flex-container {
  display: flex;
  background-color: #f0f0f0;
  padding: 10px;
}

.inline-flex-container {
  display: inline-flex;
  background-color: #f0f0f0;
  padding: 10px;
}

In this example, the .flex-container will take up the full width of its parent container, while the .inline-flex-container will only take up the space needed for its content.