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Showing posts from February, 2022

Type or Category or Classification of Design Patterns

 Type or Category or Classification of Design Patterns Creational   Based on the concept of creating an object.     Class       Factory Method This makes an instance of several derived classes based on interfaced data or events.     Object       Abstract Factory Creates an instance of several families of classes without detailing concrete classes.       Builder Separates object construction from its representation, always creates the same type of object.       Prototype A fully initialized instance used for copying or cloning.       Singleton A class with only a single instance with global access points.                    Structural   Based on the idea of building blocks of objects.     Class       Adapter Match interfaces of different classes therefore classes can work together despite incompatible interfaces.     Object       Adapter Match interfaces of different classes therefore classes can work together despite incompatible interfaces.       Bridge Separates an object's inter

Difference between webstorage, cookie, local storage & session storage

WebStorage The Window object implements the WindowLocalStorage and WindowSessionStorage objects which has localStorage(window.localStorage) and sessionStorage(window.sessionStorage) properties respectively. These properties create an instance of the Storage object, through which data items can be set, retrieved and removed for a specific domain and storage type (session or local). For example, you can read and write on local storage objects as below localStorage.setItem('logo', document.getElementById('logo').value); localStorage.getItem('logo'); What are the differences between cookie, local storage and session storage Below are some of the differences between cookie, local storage and session storage, Feature Cookie Local storage Session storage Accessed on client or server side Both server-side & client-side client-side only client-side only Lifetime As configured using Expires option until deleted until tab is closed SSL support Supported Not supported N

Cloud Computing basics

SaaS - Software as a Service is on-demand access to ready-to-use, cloud-hosted application software. E.g. Google Docs, Google Form, Google Spreadsheet.  PaaS - Platform as a Service is on-demand access to a complete, ready-to-use, cloud-hosted platform for developing, running, maintaining, and managing applications. E.g. Amazon EC2 T2 Micro instances 1 GB memory & 1 vCPU under free tier, Microsoft Azure IaaS - Infrastructure as a Service The service provides all of the infrastructures to the business. It provides on-demand access to cloud-hosted physical and virtual servers, storage, and networking - the backend IT infrastructure for running applications and workloads in the cloud. E.g. host.com that provides dedicated servers to organizations. VMware offers support for IaaS for carving out a system rack, network storage & computer into an isolated system for customers. StaaS - Storage as a Service E.g. Carbonite, Amazon S3 Storage as a service (STaaS) is a data storage busines