How can one emulate the functionality of a switch statement using objects and functions in JavaScript?

  • By creating an object where each property maps to a case label, and the corresponding values are functions to execute.
  • By using a for loop to iterate through cases and execute corresponding functions.
  • By using the "continue" keyword in a loop to simulate case behavior.
  • By creating an array of functions, where each function corresponds to a case label.
To emulate the functionality of a switch statement in JavaScript, you can create an object where each property represents a case label, and the corresponding property values are functions that perform the desired actions. You can then use the input value to access the appropriate function from the object, effectively simulating switch behavior.

How do arrow functions handle arguments in comparison to traditional functions?

  • Arrow functions don't have access to arguments.
  • Arrow functions handle arguments the same way as traditional functions.
  • Arrow functions receive arguments as a separate object.
  • Arrow functions receive arguments as individual parameters.
Arrow functions do not have access to the arguments object like traditional functions do. Instead, they handle arguments the same way as regular functions if you explicitly define parameters. Each parameter corresponds to an argument passed to the function, allowing you to access them directly within the function body. The absence of the arguments object can be a limitation in certain scenarios.

Using the new keyword invokes a _______ that creates a new object.

  • constructor
  • function
  • class
  • prototype
Using the new keyword in JavaScript invokes a constructor function that creates a new object. This object is then initialized with properties and methods defined within the constructor function. The constructor function serves as a blueprint for creating objects.

How can Cross-Origin Resource Sharing (CORS) issues be handled when using AJAX?

  • Disable CORS in the browser
  • Use JSONP for requests
  • Send requests with credentials
  • Use the 'Access-Control-Allow-Origin' header
Cross-Origin Resource Sharing (CORS) issues when using AJAX can be handled by configuring the server to include the 'Access-Control-Allow-Origin' header in its response. This header specifies which origins are allowed to access the server's resources. You can set it to '*' to allow any origin or specify specific origins. Additionally, if you need to include credentials (e.g., cookies) in your requests, you should set the 'withCredentials' property to true in your AJAX request.

You're developing a game and need to create multiple instances of a player object, each with slightly different properties. Which object creation pattern might be most appropriate to use?

  • Prototype Pattern
  • Singleton Pattern
  • Factory Method Pattern
  • Abstract Factory Pattern
In game development, you would often use the Factory Method Pattern. This pattern provides an interface for creating objects but allows subclasses to alter the type of objects that will be created. In the context of a game, you can have a PlayerFactory that creates different types of players with varying properties while maintaining a consistent creation interface.

How does the “for...of” loop differ from the traditional "for" loop?

  • It cannot iterate over arrays.
  • It can only be used for asynchronous operations.
  • It is specifically designed for iterating over arrays and iterable objects.
  • It has better performance when iterating over objects.
The "for...of" loop is used for iterating over arrays and iterable objects, providing a simplified syntax compared to the traditional "for" loop. It's particularly useful when dealing with collections of data, offering cleaner code for iteration. Traditional "for" loops are more versatile but require more verbose code for array iteration.

What is "explicit binding" in JavaScript with regard to the "this" keyword?

  • Explicit binding refers to manually setting the "this" value for a function using methods like .bind(), .call(), or .apply().
  • Explicit binding is when "this" is automatically determined by the JavaScript engine.
  • Explicit binding involves using the "this" keyword without any special methods.
  • Explicit binding is only applicable to arrow functions.
In JavaScript, "explicit binding" refers to the manual setting of the "this" value for a function. This is done using methods like .bind(), .call(), or .apply(), allowing you to explicitly specify the object that should be treated as "this" within the function. This is especially useful in cases where the default "this" behavior is not what you need.

In JavaScript, instances are typically created using the _________ keyword.

  • class
  • new
  • instance
  • create
In JavaScript, instances of objects are typically created using the new keyword. For example, you can create a new instance of a constructor function using new ConstructorName(). This keyword is essential for creating object instances.

How do you declare a two-dimensional array in JavaScript?

  • let arr = [[]];
  • let arr = [][[]];
  • let arr = [[], []];
  • let arr = [[],] [[]];
In JavaScript, a two-dimensional array is declared by creating an array where each element is another array. This creates a matrix-like structure. For example, let arr = [[], []]; declares a 2x2 two-dimensional array. The other options contain syntax errors or do not create a valid two-dimensional array.

You are working with a NodeList after querying the DOM and want to iterate over each node. Which loop would be directly usable without converting the NodeList to an array?

  • for...in loop
  • for...of loop
  • while loop
  • NodeList.prototype.forEach() method
The NodeList is not an array, but you can use the NodeList.prototype.forEach() method directly to iterate over its nodes without converting it to an array. It provides a convenient way to work with NodeLists, making it the suitable choice.