Q191. How Virtual DOM works?
The _Virtual DOM_ works in five simple steps. **1. Initial Render** When a UI component renders for the first time, it returns JSX. React uses this structure to create a ...
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Q192. Display distinct cities in ADDRESSES(id, street_name, number, city, state)?
To retrieve a list of unique cities without duplicates from the `ADDRESSES` table, use the **`DISTINCT`** keyword: ```sql SELECT DISTINCT city FROM addresses ORDER BY cit...
Q193. What is the use of the tsconfig.json file?
The tsconfig.json file is used in TypeScript to configure the compiler options for a project. It allows developers to specify settings such as target version, module syst...
Q194. What are the benefits of pure functions?
Some of the major benefits of pure functions are listed below, - **Easier testing:** Since output depends only on input, pure functions are simple to test. - **Predictabi...
Q195. What is the difference between Shadow DOM and Virtual DOM?
The _Shadow DOM_ is a browser technology designed primarily for scoping variables and CSS in _web components_. The _Virtual DOM_ is a concept implemented by libraries in ...
Q196. What is the Link component in Next.js?
A component for client side navigation between pages. ```jsx import Link from "next/link"; Home About ```
Q197. What is Vue instance?
Every Vue application works by creating a new Vue instance with the Vue function. Generally the variable vm (short for ViewModel) is used to refer Vue instance. You can c...
Q198. Select all records where FirstName is "John"?
To retrieve all columns for records where `FirstName` equals 'John', combine `SELECT *` with a `WHERE` equality filter: ```sql SELECT * FROM Customers WHERE FirstName = '...
Q199. What is the purpose of the let keyword?
The `let` keyword in JavaScript is used to declare a **block-scoped local variable**. This means that variables declared with `let` are only accessible within the block, ...
Q200. OR vs AND?
`AND` requires ALL conditions to be true. `OR` requires ANY to be true. Use parentheses to control precedence — `AND` binds tighter than `OR`. ```sql -- Without parenthes...