Design Patterns

Design Patterns are nothing but proven solutions to recurring problems.

1. Some favorite design patterns

     Creational Patterns
        - Prototype
             - used to create objects by cloning other objects
                   
        - Factory

        - Singleton

     Structural Design Patterns

      They show how the objects are composed, is there an inheritance between them, or is one object composed in another object, interfaces present


  • Proxy Pattern
           

           e.g credit card is the proxy of the Bank Account
  • Decorator
    • Adds more functionality without opening the object
    • Wraps the decorator another class, it is a component and has a component
      • Advantage - allows you to have multiple combinations among classes
  • Adapter
    • Making two interfaces which are incompatible compatible
  • Facade
    • Simplify the interactions with  too many working complex objects and complex interactions, something you want to call
    • Hides complex behavior

      Behavioral Design Patterns      e.g Iterator, Command

      Architectural Design Patterns
     e.g MVC pattern


















Comments

Post a Comment

Popular posts from this blog

Apache Airflow Wait Between Tasks

 Apache Airflow allows you to create custom workflows that can be triggered on a recurring basis at specific time intervals based on your needs. Some concepts to learn are DAGs - this defines the entire workflow Tasks - are the Individual tasks that constitute the workflow Operators - This is an airflow-specific concept, which needs to be understood, Based on what type of tasks you would like to perform there are multiple operators. To run a bash script there is a BashOperator, to run a python code you need to have a Python Operator. For more details, refer  https://airflow.apache.org/docs/apache-airflow/stable/concepts/index.html Above 3 are sufficient to get started, ofcourse there are others like interprocess communication, variables, process dependency management, etc. Let's Define a Simple Workflow we want to achieve DAG = Tasks1 >> Wait for a Day >> Task2 Above is the DAG, where two tasks are executed, second task depends on first task and is executed afte...
Read more

Groovy GoodNess – Converting a List to String

The more I work on Groovy more I love it and groovy console is a charm to try out things even for Java. Checkout the code below and Imagine if you have do the same code in Java, how much lines of Code it will be. //Converts a list say //List myList = ["user", "pwd","address1", "address2"] to //String resultStr = 'user','pwd','address1','address2' //VERSION 1 of Code Written in Groovy but Inspired by Java //Even thought the following Code is written in Groovy its, 100% of how problem would have been in Java if(!myList.empty) { //takes out the square bracket from either sides String resultStr=myList.substring(1, list_all_user_contacts.length()-1) //Relaces the "double quotes with "," resultStr=resultStr.replaceAll(",", "','") //Appends apostoles ' at the start and end resultStr="'"+resultStr+"...
Read more

Design and Agile Interview Questions

 1. what are the key design considerations when designing a form say a mortgage form   2. What are the traits you would like to see in your manager team mates      3. Every company has its own way to implement agile, elaborate your experience     -- in retrospective - we do the Sail boat analogy 4. How would you improve the performance of an application. 5. How would you make an existing application more scalabe 6. Give a big story, how would you approach it 7. if a Design team gives  say a complex diaog, but you are not in a position to implement it, how would you approach 8. How do you measure the success of your implementation any KPIs 9. How would you approach Tech debt; 10. What would you prefer, Product centric approach or Customer-centric approach
Read more