I needed to replace swedish characters from string without removing the character for itemname.

With Sitecore you can use ItemUtil.ProposeValidItemName() but it removes the invalid characters.
I have a text like “Flöde” and I want it to be “Flode” and not “Flde” like Sitecores ItemUtil does.

Then I can use the following code:

byte[] b = Encoding.GetEncoding(1251).GetBytes("Flöde/");
string output = Encoding.ASCII.GetString(b);
string validItemName = ItemUtil.ProposeValidItemName(output);

________________________
output: "Flode/"
validItemName: "Flode"

The ItemUtil.ProposeValidItemName will give you a valid item name for Sitecore.
The string output would still contain possible invalid special characters that you don’t allow in the Sitecore config setting ItemNameValidation regex.

Performance is key. We have all know this. Customers has very high expectations on fast solutions. And this is where caching is king.

There are many caching soultions out there today, like Reddis cache. You can also build your own layer if you’d like. Or you can use Sitecores.

Sitecore has their own caching framework that is used for Sitecore to get data faster. This can also be used for custom caches. So you can cache something simple as a string or even anonymous objects.

There are two types of cache you can use for customcaching.

Sitecore.Caching.CustomCache<string> and Sitecore.Caching.Generics.Cache<T>. One takes a string and one takes an object type.

Sample code

   var mycache = new Sitecore.Caching.Cache("test cache", 1024);
   mycache.Add("key", "data");

   var myType = new Type {Id = 1, Name = "Test"};
   mycache.Add("type", myType);

   //Get the value based on key
   var value = mycache.GetValue("type");

Read more:

http://sitecore-community.github.io/docs/documentation/Sitecore%20Fundamentals/Caching/