CSS: Floating divs have 0 height - html

Question

I'm trying to place 2 divs side by side inside of another div, so that I can have 2 columns of text and the outer div drawing a border around both of them:
HTML
<div id="outer">
<div id="left">
...
<div id="right">
</div>
CSS
#outer{
background-color:rgba(255,255,255,.5);
width:800px;
}
#left{
float:left;
}
#right{
width:500px;
float:right;
}
However, the outer div registers a height of 0px and so the border doesn't go around the other divs. How do I make the outer div recognize the heights of the things inside it?

Answer 1

It's not because the floating divs doesn't have a height, it's because the floating divs don't affect the size of the parent element.
You can use the overflow style to make the parent element take the floating elements in consideration:
#outer { overflow: auto; }

Answer 2

There are a couple of solutions to this issue:
#outer: overflow: hidden;
or add some non-displaying content to the outer div that comes after the floated divs that you then add a clear: both style rule to.
You can also add, through css, the :after pseudo-element to insert content after those divs that you then apply clear: both to - this has the advantage of not requiring extra markup.
My preference is the first one.

Answer 3

Try this:
<div id="outer">
<div id="left">
...
<div id="right">
<div style="clear:both"></div>
</div>

Answer 4

add overflow: hidden; to the main div.
<style type="text/css">
#outer{
background-color:rgba(255,255,255,.5);
width:800px;
overflow: hidden;
border: 1px solid green;
}
#left{
float:left;
border: 1px solid red;
}
#right{
width:500px;
float:right;
border: 1px solid yellow;
}
</style>

Answer 5

You could clear the float by inserting an element after the floated elements that has a clear property applied to it because floated child elements cause the parent to have 0 height since they don't take the height of the floated children into consideration.
<div id="outer">
<div id="left">
...
<div id="right">
<div class="clear"></div>
</div>
#outer{
background-color:rgba(255,255,255,.5);
width:800px;
}
#left{
float:left;
}
#right{
width:500px;
float:right;
}
.clear{ clear: both; }

Answer 6

You must also float the outer div.
Div's that contain floatet divs and that are not floated themselves collapse.
#outer{
background-color:rgba(255,255,255,.5);
width:800px;
float:left;
}
#left{
float:left;
width:300px;
}
#right{
width:500px;
float:right;
}

Answer 7

How bout like this:
<style type="text/css">
#outer{
background-color:rgba(255,255,255,.5);
width:800px;
border:thin solid #000000;
height:300px;
margin:5px;
padding:10px;
}
#left{
float:left;
border:thin dashed #000000;
width:385px;
height:100px;
margin:5px;
}
#right{
width:385px;
float:left;
border:thin dashed #000000;
height:100px;
margin:5px;
}
</style>
<div id="outer">
<div id="left">
</div>
...
<div id="right">
</div>
</div>

Answer 8

if div inside a parent is floated it is no longer part of parent div:check it by inspecting parent element.no to fix your problem there are two methods:
1)make a empty div at end inside parent class it as .blank all following css
.blank:after{
content: "";
clear:both;
display:block;
}
Or
2) give parent a class .clear-fix and add css
.clearfix:after {
content: "";
clear: both;
display: block;
}
it will give parent a height equal to contents