For example when you paste the following from Xcode to Evernote

extern NSString *const APP_VERSION;
extern NSString *const APP_NAME;
extern NSString *const APP_CFG_CATEGORY_APP;

it removes the spaces as show below:

externNSString *const APP_VERSION;
externNSString *const APP_NAME;
externNSString *const APP_CFG_CATEGORY_APP;

Answer

The key here is to Paste the text using Shift+Cmd+V instead of using regular paste hotkey Cmd+V.