title: Why would you use the keyword const if you already know variable should be constant?
body: <p>Many of the books that I am reading use keyword <code>const</code> when the value of a variable should not be modified. Apart from specifying to readers of the code that you may cause errors if you modify this variable (you can use comments to do this), why would you need that keyword to be a part of any programming language? It seems to me that if you don't want a variable modified, simply don't.</p>
  
  <p>Could someone clarify this for me? </p>