Don’t Repeat Yourself (DRY) is a software development principle, the main aim of which is to reduce repetition of code. Write Everything Twice (WET) is…
S.O.L.I.D. Stands for S — Single responsibility principle O — Open closed principle L — Liskov substitution principle I — Interface segregation principle D —…
Callback A callback is a function that will be executed when an asynchronous operation has been completed. Since setTimeout is asynchronous operation, sayHello function can be…
AWS SNS Overview SNS is Pub-Sub service for messaging. Publish messages to subscriber via topics Subscribers have to subscribe topic in order to receive messages…
AWS SQS Overview SQS provides two types of Queues – Standard & FIFO Amazon SQS is a highly available distributed queue system It helps to…
In Javascript, data type can be categories into two main types. Primitive types (value type) and none Primitive types (Reference type). each type has its…
Overview Amazon Elastic Compute Cloud (Amazon EC2) provides scalable computing capacity in the Amazon Web Services (AWS) cloud. Using Amazon EC2 eliminates your need to…
Overview Regular expression is one of extremely useful technique to extract matching patterns from text. It has been used in many places, such as simple…
Overview Today many developers try to optimizing query in order to get high performance of the application. I had a chance to optimize many queries…
npm and npx overview I’m pretty sure, everyone knows that what is npm. Its a package manager for nodejs. similar to bower, nuget, homebrew, yum,…