The method _______ can be used to add new elements to the end of an array.
- push()
- unshift()
- add()
- append()
The push() method in JavaScript can be used to add new elements to the end of an array. This method modifies the original array and is commonly used when you want to add elements to the end of an array, expanding its length. For example, myArray.push('newElement') would add 'newElement' to the end of myArray.
What value types can be used for case comparisons in a switch statement?
- Strings, numbers, and symbols
- Arrays, objects, and booleans
- Only numbers and booleans
- Functions and undefined values
In a switch statement, you can use strings, numbers, and symbols as values for case comparisons. These values are compared strictly, meaning both value and type must match for the associated code block to execute.
In what scenario might you prefer to use a function expression over an arrow function?
- When needing a concise syntax.
- When you want to bind this explicitly.
- When working with callbacks in event handling.
- When using async/await for asynchronous code.
You might prefer to use a function expression (a regular function) over an arrow function when you need to explicitly bind the this context, especially in cases where you want to define methods inside objects or use constructors. Function expressions allow you to use the this keyword as expected, while arrow functions inherit this from their lexical enclosing context.
You are debugging a piece of code and encounter a variable declaration let [a, b, ...rest] = [10, 20, 30, 40, 50];. What will be the value of rest?
- [30, 40, 50]
- [10, 20]
- [20, 30, 40, 50]
- [undefined, undefined]
The value of rest will be [30, 40, 50]. This code uses destructuring assignment to assign the first two elements to a and b, and the rest of the elements to rest using the rest parameter (...). So, a will be 10, b will be 20, and rest will contain [30, 40, 50].
When you want to store multiple values in a single variable, you should use a(n) _________.
- "array"
- "object"
- "string"
- "function"
To store multiple values in a single variable in JavaScript, you should use an array. An array is a data structure that can hold multiple values of different data types. It is created using square brackets, like this: var myArray = [value1, value2, value3];. Arrays are versatile and commonly used for tasks like storing lists of items or organizing data.
Which property allows you to change the HTML content of an element?
- textContent
- innerText
- innerHTML
- innerTextContent
The innerHTML property allows you to change the HTML content of an element in JavaScript. It is often used to set or modify the content of an element and can include HTML tags. However, be cautious when using innerHTML to avoid potential security issues, such as cross-site scripting (XSS).
If you want to convert a JavaScript object to a string in the Fetch API, you should use the _________ method.
- parse()
- serialize()
- stringify()
- convert()
In the Fetch API, you should use the JSON.stringify() method to convert a JavaScript object to a string. This method serializes the object into a JSON string, which is a common way to send structured data in HTTP requests and responses. parse() is used for JSON parsing.
The ________ interface provides methods to deal with HTTP responses represented in binary format.
- a) TextDecoder Interface
- b) FormData Interface
- c) Blob Interface
- d) ArrayBuffer Interface
The Blob interface provides methods to deal with HTTP responses represented in binary format. It allows you to work with binary data such as images, audio, or other binary content in a more efficient way. This is essential when handling binary data in web applications.
You're debugging a piece of code and find an unexpected type coercion in a comparison. Which operator is most likely being used that could cause this issue?
- == (Equality)
- === (Strict Equality)
- > (Greater Than)
- != (Inequality)
The double equal operator (==) performs type coercion during comparison, which means it converts the operands to the same type before comparing. This can lead to unexpected results when comparing values of different types, potentially causing type coercion issues in your code. You should generally prefer strict equality (===) to avoid type coercion.
How does the temporal dead zone impact function expressions in JavaScript?
- It prevents the use of arrow functions in function expressions.
- It enforces a delay in the execution of function expressions.
- It causes a runtime error if a variable is accessed before its declaration in a function.
- It makes function expressions execute before other code in the same scope.
The temporal dead zone (TDZ) is a phase during the variable initialization in JavaScript. It occurs between the variable's declaration and its assignment. During this phase, trying to access the variable will result in a ReferenceError. This impacts function expressions as variables declared within them are also subject to the TDZ. If you try to access such a variable before its declaration, it will lead to a runtime error.