To insert a variable into a template literal, use the ${} __________.
- Parentheses ()
- Curly braces {}
- Square brackets []
- Angle brackets <>
To insert a variable into a template literal, use the ${} syntax with curly braces. This allows for dynamic content within the string, making it more flexible and readable.
Static methods are often used for _________ that are relevant to all instances of a class.
- Properties
- Functionality
- Events
- Callbacks
In object-oriented programming, static methods are associated with a class rather than instances. They are often used for functionality that is relevant to all instances of a class, rather than a specific instance. This helps in organizing code and improving code readability.
How does the Symbol type interact with the Object.getOwnPropertySymbols() method?
- It returns an array of all symbol properties found directly upon the given object.
- It throws an error since symbols are not enumerable.
- It returns an object containing all symbol properties found directly upon the given object.
- It only returns symbols with specific descriptors.
The Object.getOwnPropertySymbols() method returns an array of all symbol properties found directly upon the given object, regardless of their enumerability. It allows you to access symbols that are not enumerable in regular object iteration.
The _________ pattern in ES6 is a design pattern used to compose objects from small reusable components.
- Factory
- Composite
- Mixin
- Observer
The correct option is Mixin. In ES6, the Mixin pattern involves composing objects by combining small, reusable components. This allows for better code organization and reusability. Mixins are a way to enhance a class with the methods of another class without the need for inheritance.
Can you access instance properties from a static method?
- Yes, using the this keyword.
- No, it results in a runtime error.
- Yes, using the super keyword.
- No, instance properties are inaccessible.
No, you cannot access instance properties directly from a static method. Static methods are associated with the class itself and do not have access to instance-specific data. Option D is correct.
What is a mixin in the context of JavaScript ES6?
- A way to create variables in ES6
- A function that takes two objects and returns a new object
- A method for adding properties and methods to a class
- A type of loop in ES6
In JavaScript ES6, a mixin is a way to compose classes by adding properties and methods to a class. It allows the reuse of functionalities and promotes code reusability. Unlike inheritance, mixins do not rely on a hierarchical relationship between classes. They enhance the flexibility and maintainability of code.
How do default parameters interact with destructuring assignment in function arguments?
- They can't be used together
- Destructuring assignment takes precedence
- The function ignores the default parameters
- Destructuring is not supported in ES6
Default parameters and destructuring can be used together, and destructuring takes precedence. Explanation should elaborate on how they work together.
Functions that perform HTTP requests are not considered pure because they _________.
- Use Arrow Functions
- Have Side Effects
- Are Asynchronous
- Are Synchronous
Functions that perform HTTP requests are not considered pure because they have side effects. Purity in functions means that they do not cause any observable side effects, and HTTP requests involve external actions that can impact the program's state.
When a const variable is declared in a block scope, what is the scope of this variable?
- Local to the block
- Global
- Function-level
- Lexical scope
In JavaScript, when you declare a constant variable (const) inside a block (like an if statement or a loop), the scope of that variable is limited to the block. This means it cannot be accessed outside of that block.
If a project is using a third-party library with multiple components, but only a few are needed, how can tree shaking be utilized for efficiency?
- Import only the needed components from the library in the code.
- Include the entire library as is.
- Manually remove unused components from the library.
- Use a separate smaller library for the required components.
Tree shaking can be leveraged by importing only the necessary components from the third-party library. This way, the bundler can exclude the unused parts during the build process, optimizing the bundle size. The other options are not efficient for tree shaking purposes.