JavaScript Mid
What is ArrayBuffer?
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ArrayBuffer is a type of object used to represent a fixed-length raw binary data buffer.
ArrayBuffer is used to style HTML elements.
ArrayBuffer is a server-side technology.
ArrayBuffer is used to manage browser cookies.
What is polyfill?
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A polyfill is used to manage browser cookies.
A polyfill is a server-side technology.
A polyfill is used to style HTML elements.
A polyfill is code that provides modern functionality in older environments that do not natively support it.
What are modules?
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Modules are used to style HTML elements.
Modules are reusable pieces of code that can be imported and exported.
Modules are used to manage browser cookies.
Modules are server-side components.
What is Object.freeze?
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Object.freeze prevents modifications to an object.
Object.freeze styles HTML elements.
Object.freeze duplicates an object.
Object.freeze allows modifications to an object.
What is type coercion?
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Type coercion is the process of declaring variables.
Type coercion is the manual conversion of values from one type to another.
Type coercion is the automatic conversion of values from one type to another.
Type coercion is used for styling HTML elements.
Explain the spread/rest operator (...) in ES6.
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The spread operator (...) expands iterable values, and the rest operator (...) condenses multiple elements into an array.
The spread operator (...) condenses multiple elements into an array, and the rest operator (...) expands iterable values.
The spread operator (...) and the rest operator (...) are used for styling HTML elements.
The spread operator (...) is used only for objects, and the rest operator (...) is used only for arrays.
What are the difference between es5 and es6?
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ES5 introduced features like arrow functions, classes, and template literals.
ES6 is used for backend development only.
ES6 is the same as ES5 with no new features.
ES6 introduced features like arrow functions, classes, and template literals.
How do you determine two values same or not using object in JavaScript?
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To determine if two values are the same, use Object.is method.
To determine if two values are the same, use Object.copy method.
To determine if two values are the same, use Object.compare method.
To determine if two values are the same, use Object.equal method.
What is the Event Loop in JavaScript, and how does it work?
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The Event Loop in JavaScript manages browser cookies.
The Event Loop in JavaScript styles HTML elements.
The Event Loop in JavaScript compiles the code.
The Event Loop in JavaScript manages the execution of asynchronous code.
What is optional chaining?
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Optional chaining is used to import modules.
Optional chaining is a feature that allows safe access to nested object properties.
Optional chaining is used to style HTML elements.
Optional chaining is used to declare variables.
What is a Cross-Origin Resource Sharing (CORS) policy, and how does it work?
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Cross-Origin Resource Sharing (CORS) policy is used to compile JavaScript code.
Cross-Origin Resource Sharing (CORS) policy allows restricted resources on a web page to be requested from another domain.
Cross-Origin Resource Sharing (CORS) policy is used to style web pages.
Cross-Origin Resource Sharing (CORS) policy is a server-side technology.
What is Cross-Site Scripting (XSS) in web security, and how can you prevent it?
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Cross-Site Scripting (XSS) is a server-side technology.
Cross-Site Scripting (XSS) is used to manage browser cookies.
Cross-Site Scripting (XSS) is a method to style web pages.
Cross-Site Scripting (XSS) is a security vulnerability that allows attackers to inject malicious scripts into web pages.
What is a pure function?
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A pure function is a function that has no side effects and returns the same output for the same input.
A pure function is a function that can only be used in synchronous code.
A pure function is a function that only works with strings.
A pure function is a function that always returns a promise.
What is a higher-order function?
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A higher-order function is a function that only works with arrays.
A higher-order function is a function that always returns a promise.
A higher-order function is a function that is always asynchronous.
A higher-order function is a function that takes another function as an argument or returns a function.
What is ECMAScript?
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ECMAScript is a CSS framework.
ECMAScript is a JavaScript library.
ECMAScript is a server-side language.
ECMAScript is the standard on which JavaScript is based.
What is AJAX, and how does it work in JavaScript?
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AJAX is used to compile JavaScript code.
AJAX allows web pages to be updated asynchronously by exchanging data with a server.
AJAX is used to style web pages.
AJAX is a server-side technology.
What is the difference between double (==) and triple (===) equals in JavaScript?
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Double equals (==) checks for value equality, triple equals (===) checks for value and type equality.
Double equals (==) checks for value and type equality, triple equals (===) checks for value equality.
Double equals (==) and triple equals (===) are the same.
Double equals (==) checks for object reference equality, triple equals (===) checks for array equality.
Is JavaScript pass by reference or pass by value?
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JavaScript is always pass by reference.
JavaScript is pass by value for primitives and pass by reference for objects.
JavaScript is pass by reference for primitives and pass by value for objects.
JavaScript is always pass by value.
What is the difference between the client side and server side?
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Client side and server side do not perform operations.
Client side refers to operations on the user's browser, server side refers to operations on the server.
Client side refers to server operations, server side refers to browser operations.
Client side and server side are the same.
What is NaN?
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NaN stands for Not-a-Number, representing a valid number.
NaN stands for Not-a-Number, representing an invalid number.
NaN stands for Number-and-Null.
NaN stands for Null-and-Number.
What is the difference between null and undefined?
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null and undefined are used to declare variables.
null and undefined are the same.
null represents the uninitialized state, undefined represents the intentional absence of value.
null represents the intentional absence of value, undefined represents the uninitialized state.
What is the difference between a shallow and a deep copy?
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Shallow copy and deep copy are the same.
Shallow copy and deep copy do not duplicate properties.
A shallow copy duplicates only the top-level properties, a deep copy duplicates all nested properties.
A shallow copy duplicates all nested properties, a deep copy duplicates only the top-level properties.
What are template literals (template strings) in ES6?
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Template literals are used to import modules.
Template literals are used to declare variables.
Template literals are string literals allowing embedded expressions.
Template literals are used to style HTML elements.
What is the role of a package manager like npm or yarn in JavaScript development?
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A package manager like npm or yarn styles HTML elements.
A package manager like npm or yarn manages dependencies and packages in JavaScript.
A package manager like npm or yarn manages browser cookies.
A package manager like npm or yarn compiles JavaScript code.
What is the difference between event bubbling and event capturing?
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Event capturing propagates events from child to parent, event bubbling from parent to child.
Event bubbling and event capturing are the same.
Event bubbling and event capturing do not propagate events.
Event bubbling propagates events from child to parent, event capturing from parent to child.
How to prevent event bubbling?
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To prevent event bubbling, use the stopPropagation method.
To prevent event bubbling, use the preventDefault method.
To prevent event bubbling, use the stopImmediatePropagation method.
To prevent event bubbling, use the addEventListener method.
Explain event bubbling in JavaScript?
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Event bubbling is used to prevent event default behavior.
Event bubbling is the event propagation from parent to child elements.
Event bubbling stops the event from being propagated.
Event bubbling is the event propagation from child to parent elements.
Explain Promise.all.
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Promise.all executes promises in sequence.
Promise.all is used to handle synchronous operations.
Promise.all returns the first resolved promise.
Promise.all takes an array of promises and returns a single promise.
What is callback hell?
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Callback hell refers to the situation where callbacks are nested within other callbacks.
Callback hell is when callbacks are executed in parallel.
Callback hell occurs when callbacks are used in synchronous code.
Callback hell is when callbacks are used to manage CSS styles.
What are Promises?
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Promises are used to handle asynchronous operations in JavaScript.
Promises are used to manage CSS styles.
Promises are used to declare variables.
Promises are used to perform mathematical operations.
What are callback functions?
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Callback functions are used to style HTML elements.
Callback functions are functions that call themselves recursively.
Callback functions are only used in synchronous code.
Callback functions are functions passed into another function as an argument.
Explain synchronous vs asynchronous programming.
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Synchronous programming is used for styling, while asynchronous programming is used for scripting.
Synchronous programming allows tasks to run concurrently, while asynchronous programming executes tasks sequentially.
Synchronous programming executes tasks sequentially, while asynchronous programming allows tasks to run concurrently.
Synchronous programming is only used in frontend development, while asynchronous programming is used in backend development.
What is the difference between Session Storage and Local Storage?
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Local Storage can only store strings, Session Storage can store objects.
Session Storage can store more data than Local Storage.
Local Storage data is cleared when the page session ends, Session Storage persists.
Session Storage data is cleared when the page session ends, Local Storage persists.
Explain the concept of closures in JavaScript
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Closures are used to style HTML elements.
Closures allow functions to access variables from an outer function scope.
Closures prevent functions from accessing variables from an outer function scope.
Closures are used to import modules.
What are the main differences between arrow and regular functions?
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Arrow functions are always synchronous.
Arrow functions do not have their own this context.
Arrow functions cannot accept arguments.
Arrow functions cannot be assigned to variables.
What is the difference between function declaration and function expression JavaScript?
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Both function declarations and function expressions are hoisted.
Neither function declarations nor function expressions are hoisted.
Function expressions are hoisted, function declarations are not.
Function declarations are hoisted, function expressions are not.