var_and_let sample.js

function howVarWorks()
{
  //i is also visible here.
  for( var i = 0 ; i<10 ;i++)
  {
    //i is visible everywhere in the function
  }
  //i is also visible here.
}

function howLetWorks()
{
  //j is *not* visible here.
  for(let j = 0 ; j<10 j++)
  {
    //j is only visible here.
  }
  //j is *not* visible here.
  
}