Explanation on CSS float overflow property - css

Question

I am a newbie to CSS. I started exploring CSS float property. I have two <div> elements inside a container. The two divs have equal width and height.
<div class="container">
<div class="one">
</div>
<div class="two">
<p>
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,
</p>
</div>
</div>
And CSS for the above is :
.one{
width: 200px;
height: 200px;
background-color: green;
border: 1px solid blue;
float: left;
}
.two{
width: 200px;
height: 200px;
background-color: red;
border: 1px solid black;
overflow:visible;
}
.container{
overflow:hidden;
}
From the above what I can understand is that since the div that is floated is removed from the normal flow and floated to left and the second div which contains the text inside <p> elements merges underneath the .one div. And moreover since both have the same width and height I cannot see the content.
But when I set the overflow property of the .two to scroll I see the second div being placed adjacent to first div. This is confusing. Why is such a behavior? Please explain me. Link to codepen attached below for more details.
Link to Codepen

Answer 1

The float CSS property specifies that an element should be taken from the normal flow. However the non-float element still takes all the available width including the floating element. But if you set overflow: auto; or hidden to it, it will then align next to the floating element. See the demo following, it should explain it clearly.
.a1, .b1 {
background: rgba(0,0,0,.5); /*pure black with alpha*/
width: 50px;
height: 50px;
float: left;
}
.a2 {
background: lime;
}
.b2 {
background: lime;
overflow: auto; /*let the browser decide whether to clip or not*/
}
<div class="a1">hello</div>
<div class="a2">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu.</div>
<br/>
<div class="b1">hello</div>
<div class="b2">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu.</div>

Answer 2

What is happening here is because:
.container{
overflow:hidden;
}
What is happening?
Your floating div wants to take up space before your other div. Because your non-floating div has display: block, it wants a whole line to render itself. The floating div is pushing down your non-floating div which is then hidden by the style above. If you change display to inline-block, it will take up only the space it needs using the width and height properties.
Here is an example: http://codepen.io/anon/pen/LVpxZy