title: What is best way to keep constants separated from Salesforce  apex code?
body: <p>If I need to keep some config separated out from code then what should be the best approach? I have some Web Services that needs to be invoked from Apex class.  Web Services URL vary based from where it was invoked i.e if Apex code is deployed on Sandbox then it needs to invoke <a href="http://www.sandbox.com/XXX" rel="nofollow">http://www.sandbox.com/XXX</a> while if in Production then it needs to use <a href="http://www.production/XXX" rel="nofollow">http://www.production/XXX</a>.</p>