function readOnly(count){ }
Starting November 20, the site will be set to read-only. On December 4, 2023,
forum discussions will move to the Trailblazer Community.
+ Start a Discussion
Rabbani sayyed 8Rabbani sayyed 8 

When we use interface and when we use abstract class

pconpcon
Since you provide a question with faily minimal details, I'm just going to give you some things to read [1] [2].  If after reading those you have any specific questions about the topics or how to implement them in Salesforce, please let me know.

[1] https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_classes_interfaces.htm
[2] http://www.javaworld.com/article/2077421/learn-java/abstract-classes-vs-interfaces.html