basic_for_loop.cs

List<Market> markets = api.GetMarkets(MarketType.FX);

/*  
 * Using a primitive for loop
 *  - Opportunity for off by one errors
 *  - Syntax noise - declaring an empty List, thinking about i & markets[i]
 */
List<Market> openMarkets = new List<Market>();
for(int i=0; i < markets.Count; i++) 
{
   if (markets[i].IsOpen)
     openMarkets.Add(market[i]);
}


/*  
 * Using a higher order "each" loop
 *  - No more syntax noise with i; or possibility of off by one errors
 *  - But, still extra syntax noise - declaring an empty List, 
 *  - Most important statement - market.IsOpen() obscured by foreach & List.Add syntax
 */
List<Market> openMarkets = new List<Market>();
foreach(Market market in markets) 
{
   if (market.IsOpen)
     openMarkets.Add(market);
}

filter.js

markets.filter( function(market) { 
                   return market.IsOpen;
                 });

filter_using_Where.cs

/*  
 * Using a higher order function Where()
 *  - No more noise around declaring empty list
 *  - The most important statement - market.IsOpen() - has prominence.
 */
List<Market> openMarkets = markets.Where(market => market.IsOpen);

map_using_array.map.js

var inflatedStockItems = stockItems.map(function(stockItem) {           
                                          stockItem.price = stockItem.price * INFLATION; 
                                          return stockItem;
                                       });

map_using_for.js

var INFLATION = 1.05;
var stockItems = api.GetStockItems();

var inflatedStockItems = [];
for(stockItem in StockItems) {
   var inflatedStockItem = dojo.clone(stockItem);                 // http://dojotoolkit.org/api/1.5/dojo.clone
   inflatedStockItem.price = inflatedStockItem.price * INFLATION;  
   inflatedStockItems.push(inflatedStockItem);
}

   

map_using_select.cs

var inflatedStockItems = stockItems.Select( (stockItem) => { 
                                                 stockItem.Price *= INFLATION; 
                                                 return stockItem;
                                          });