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Experienced JS

  1. Prototype Design Pattern:
    The Prototype Design Pattern is a creational design pattern that involves creating new objects by copying an existing object, known as the prototype. This pattern promotes efficiency by allowing objects to be instantiated with pre-existing configurations rather than creating them from scratch. It is particularly useful in scenarios where the cost of creating a new instance is more expensive than copying an existing one.

  2. WeakMap in ES6:
    In ES6, a WeakMap is a collection of key-value pairs where keys must be objects. Unlike a regular Map, a WeakMap allows for more efficient memory management by not preventing the garbage collection of its keys. This means that if there are no other references to a key, it can be automatically removed from the WeakMap. This behavior distinguishes WeakMap from Map, where references to keys are maintained, preventing their disposal.

  3. Advantage of Arrow Syntax for Constructor Method:
    Using arrow syntax for a constructor method in JavaScript provides a concise and elegant way of defining functions. The primary advantage is the lexical binding of the this keyword, which ensures that it retains the value of this from the surrounding scope. This eliminates the need to explicitly bind this within the constructor, resulting in more readable and less error-prone code.

  4. Temporal Dead Zone:
    The Temporal Dead Zone (TDZ) is a phase in JavaScript during which a variable declared with let or const is inaccessible and accessing it results in a ReferenceError. This occurs from the start of the block where the variable is declared until the actual declaration is encountered in the code execution. It emphasizes the importance of understanding variable hoisting and encourages developers to declare variables before using them in the code.

  5. Difference between Set and WeakSet in ES6:
    In ES6, both Set and WeakSet are collection objects, but they differ in their handling of object references. A Set can store any type of value, and references to its elements are maintained, preventing them from being garbage collected. On the other hand, a WeakSet only accepts object references and allows them to be garbage collected if there are no other references, making it suitable for scenarios where automatic memory management is desired.

  6. Proxy in ES6:
    In ES6, a Proxy is an object that wraps another object, intercepting operations like property access, assignment, and method invocation. This enables developers to customize the behavior of fundamental operations. Proxies are often used for tasks such as validation, logging, and implementing features like lazy loading. They provide a powerful mechanism for meta-programming and controlling object interactions.

  7. Difference between const and Object.freeze():
    The const keyword in JavaScript is used to declare variables with constant values, preventing reassignment. However, it does not guarantee immutability for complex objects. Object.freeze() is a method that, when applied to an object, prevents its properties from being added, modified, or removed. While const restricts reassignment, Object.freeze() enforces immutability for the entire object, providing a higher level of protection.

  8. IIFE (Immediately Invoked Function Expressions):
    The provided code does not work as an IIFE because it lacks the necessary enclosing parentheses. To transform it into an IIFE, the code should be modified as follows:

   (function() {
       // Your code here
   })();
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The parentheses ensure that the function expression is immediately invoked, creating a self-contained and executed code block.

  1. Internationalization and Localization:
    Internationalization (i18n) involves designing software to support multiple languages and regions without modifying the underlying code. Localization (l10n) is the process of adapting the software for a specific locale, including translating text, adjusting date and time formats, and accommodating cultural differences. For example, an application supporting internationalization might have separate language files, allowing users to switch between English and French versions.

  2. Webpack:
    Webpack is a widely used open-source JavaScript module bundler. It takes various assets, such as JavaScript, CSS, and images, and transforms them into bundles that can be efficiently loaded by web browsers. Webpack simplifies the management of dependencies, optimizes assets for performance, and facilitates the modular organization of code. For instance, it can combine multiple JavaScript files into a single bundle, reducing the number of requests made by a web page.

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