Button at the center and bottom of div

Question

How to make a button be at the bottom of div and at the center of it at the same time?

Answer 1

For example write like this if you have position absolute:

.btn-bot{
   position:absolute; 
   margin-left:-50px;
   left:50%;
   width:100px;
   bottom:0px;
}

Note: give margin-left half of the width of the button.

JSFiddle demo