This gist just shows some good usage and bad usage examples about Hoisting concept in Javascript.

bad_hoisting.js

function stepSum() {
  var total = 0;
  for (var i = 0; i < arguments.length; i++) {
    var parameter = arguments[i];
    if (typeof(parameter) !== 'number') {
      parameter = parseInt(parameter);
    }
    setTimeout(function() {
      if (!isNaN(parameter)) {
        total += parameter;
        console.log(i + ") adding " + parameter + 
                    ", total is now " + total);
      }
    }, i*1000);
  }
  return "the stepSum has been triggered...";
}

client.js

stepSum(3, 2, 1);

good_hoisting.js

function stepSum() {
  var parameter, printStep,
      total = 0,
      i = 0;
 
  // printStep function
  printStep = function(parameter, step) {
    step++;
    setTimeout(function() {
      if (!isNaN(parameter)) {
        total += parameter;
        console.log(step + ") adding " + parameter + 
                    ", total is now " + total);
      }
    }, step * 1000);
  };
 
  // Iterating
  for (i = 0; i < arguments.length; i++) {
    parameter = arguments[i];
    if (typeof(parameter) !== 'number') {
      parameter = parseInt(parameter);
    }
    printStep(parameter, i);
  }
  return "the stepSum has been triggered...";
}