Bad.js

MyEventManager.prototype.bootstrap = function ( ) {
  var self = this;
  this.listen( 'myEvent', function ( ) {
    self.myEventListener( );
  } );
};

// ---

var array = [ 1, 2, 3 ];
for ( var t = 0, l = array.length; t < l; ++ t )
  doOp( array[ t ] );

// ---

var array = [ 1, 2, 3 ];
for ( var sum = 0, t = 0, l = array.length; t < l; ++ t )
  sum += array[ t ];

Good.js

MyEventManager.prototype.bootstrap = function ( ) {
  this.listen( 'myEvent', this.myEventListener.bind( this ) );
};

// ---

var array = [ 1, 2, 3 ];
array.forEach( function ( n ) {
  doOp( n ); } );

// ---

var array = [ 1, 2, 3 ];
var sum = array.reduce( function ( sum, n ) {
  return sum + n; }, 0 );