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June 27, 2021 Ravi Yasas
List vs Queue vs Set vs MapListQueueSetMapDuplicatesYesYesNoNo(Allow duplicate values not keys)OrderYesYesNoNoNull valuesYesPriority queue doesn't allow, but queue using LinkedList allows nullSingle nullSingle null key and many null valu...
beginners / coding / collection framework / collections / learning / list / map / queue / set / tutorial
June 27, 2021 Ravi Yasas
HashMap vs HashTable HashMapHashTableNot synchronizedSynchronizedAllows one null key and many null valuesDoesn't allow null valuesNo orderLinkedHashMap - Insertion orderTreeMap - order by keysNo orderNo duplicatesNo duplicat...
June 27, 2021 Ravi Yasas
ArrayList vs LinkedList vs Vector ArrayListLinkedListVectorData structureIndex-based dynamic arrayDoubly linked listGrowable arrayIncrement size50%No initial size100%Traverse Uses iteratorUses iteratorUses enumerationMemory usageLess memory usageMore memory usageAccessibilityRandom...
array / arraylist / beginner / collection framework / collections / devloper / typesafety / vector
June 27, 2021 Ravi Yasas
ArrayArrayListFixed-sizeSize is not fixedNot type-safeType-safeAllow both primitives and objectsDoesn't allow primitives. But after Java 5 auto-boxing will convert primitives to objectsType safety means the compiler will validate the types while compiling and throw an error if you do anything...
array / arraylist / beginner / collection framework / collections / devloper / typesafety
June 26, 2021 Ravi Yasas
RESTIntroductionStands for Representational State Transfer.REST is a web standards-based architecture that uses the HTTP protocol (port 80) for data communication.Uses HTTP methods for data communication REST server simply provides access to resources and client access and presents the resource.REST...
June 26, 2021 Ravi Yasas
DirectivesDirectives are instructions in the DOMIt adds additional behaviors to the elementsUsing inbuilt directives we can manage forms, lists, styles, and what users see.There are a few typesComponent directivesAttribute directivesStructural directivesComponent directivesThese directives are...
angular / angular 11 / angular tutorial / attribute / beginners / component / directives / learning / structural / tutorial
June 26, 2021 Ravi Yasas
Access token vs refresh tokenAccess tokenThis is short-livedSend API request, with the access tokenIf the access token is invalid, fail and ask the user to re-authenticateThere are few types of access tokensBearer tokensJWT tokensOpaque tokenRefresh tokenThese tokens are long-livedRefresh tokens are...
Read this article for more details about using dotenv with NestJS.
