🔑 What are Access Modifiers? Access modifiers define the visibility or accessibility of classes, methods, and variables. They control who can access what in your program. Java has four main access modifiers: ModifierClassPackageSubclassWorld (anywhere)private✔✖✖✖default✔✔✖✖protected✔✔✔✖public✔✔✔✔ “Default” access is when no modifier is specified. 🔑 1. Private Accessible only within the same class. Used to encapsulate…
Operators are special symbols in Java that perform operations on variables and values. They are essential in expressions, calculations, comparisons, and logical decisions. Here’s a complete breakdown: 🔑 1. Arithmetic Operators Used for mathematical calculations. OperatorDescriptionExample+Addition5 + 3 = 8-Subtraction5 - 3 = 2*Multiplication5 * 3 = 15/Division10 / 2 = 5%Modulus (remainder)10 %…
The Object class in Java is one of the most fundamental concepts. Let’s break it down clearly. 🔑 What is the Object Class? Object is the root superclass of all classes in Java. Every class implicitly extends Object if it does not explicitly extend another class. It is part of the java.lang package. class…
The Runtime class in Java is part of the java.lang package and is a singleton class that provides a way to interface with the Java Virtual Machine (JVM) at runtime. It lets your program interact with the environment, such as memory management, executing system commands, or exiting the program. 🔑 Key Features of Runtime…
The System class in Java is a final class in java.lang package that provides useful system-related utilities. It cannot be instantiated (constructor is private), and all of its members are static. 🔑 Features of System Class Here are the main things you can do with it: 1. Standard Input, Output, Error Streams System.out →…
In Java, both StringBuffer and StringBuilder are classes used to create and manipulate mutable strings (unlike String, which is immutable). Here’s the comparison: 🔑 1. Mutability Both StringBuffer and StringBuilder create mutable string objects (content can be changed without creating new objects). 🔑 2. Thread Safety StringBuffer Thread-safe, because its methods are synchronized. Suitable…
csscsspackage managerpackage managerlinterslintersmodule bundlermodule bundlertestingtestingtypescripttypescriptspaspaReactjsReactjsAngularAngularhttphttpgraphqlgraphqlSecuritySecurityIdentity and Access Management (IAM)Identity and Access...SSOSSORBACRBACOAuth2 / OpenID ConnectOAuth2 / OpenID Conn...JWTJWTCSPCSPJWT ValidationJWT ValidationIDTokenIDTokenAccess TokenAccess TokenCSPCSPOWASPOWASPSSL/TLSSSL/TLSCORSCORScode & methodscode & methodsnpmnpmyarnyarntoolstoolsBrowser DevToolsBrowser DevToolsfundamentalsfundamentalsadvancedadvancedeslinteslintprettierprettierwebpackwebpackcypresscypressREST ApiREST ApiProgressive Web AppsProgressive Web AppsServer-Side RenderingServer-Side RenderingjestjestAngular CLIAngular CLIproject structureproject structureModulesModulesComponentComponentDecoratorDecoratorpipespipesservices and DIservices and DItemplates and databindingtemplates and databi...routingroutingFormsFormsRxjsRxjsHttpHttpLifecycle HooksLifecycle Hooksroute gaurdsroute gaurdsRouterModuleRouterModuleHttpClientModuleHttpClientModuleInterceptorsInterceptorsRxjx OperatorsRxjx OperatorsObservable &…
Basic OperationsBasic OperationsComplex QueriesComplex QueriesViewsViewsStored Procedures and FunctionsStored Procedures an...Triggers and EventsTriggers and EventsTransactionsTransactionsIndexesIndexesSecurity and PermissionsSecurity and Permiss...Querying dataQuerying dataModifying dataModifying dataFiltering data Filtering data OperatorsOperatorsSorting and limiting data Sorting and limiting...Aggregate functionsAggregate functionsBEGIN, COMMIT, ROLLBACK BEGIN, COMMIT, ROLLB...Joins (INNER, OUTER, SELF, NATURAL, CROSS) Joins (INNER, OUTER,...Grouping data (GROUP BY, HAVING, ROLLUP)Grouping data (GROUP...SubqueriesSubqueriesadvanced functionsadvanced functionsN+1 problemN+1 problemDataTypesDataTypesDDLDDLPrimary Keys…
What is a Replica Set? A replica set is a group of database servers that maintain the same dataset to provide redundancy and high availability. Essentially, it’s a way to make your database fault-tolerant: if one server fails, another can take over with minimal downtime. Key Points: Primary: Receives all write operations. There is…
1. CREATE (Insert Documents) Insert one document: db.collectionName.insertOne({ name: "Alice", age: 25, city: "New York" }); db.collectionName.insertOne({ name: "Alice", age: 25, city: "New York" }); Insert multiple documents: db.collectionName.insertMany([ { name: "Bob", age: 30, city: "Los Angeles" }, { name: "Charlie", age: 28, city: "Chicago" } ]); db.collectionName.insertMany([ { name: "Bob", age: 30, city:…