The following list is a representation of an array.
The next list is a representation of the previous array being transformed by the following code:
dojo.map(original, function(item, index){ return { id: index * 100, text: item }; });
The final list is a representation of the mapped array being filtered by the following code:
dojo.filter(mapped, function(item, index){ return item.id > 50 && item.id < 350; });