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.
Which method is commonly used to iterate through elements of an array in JavaScript?
- for...in loop
- forEach() method
- while loop
- map() method
The forEach() method is commonly used to iterate through elements of an array in JavaScript. It allows you to execute a provided function once for each array element, making it a straightforward choice for looping through arrays. The other options, such as for...in loop, while loop, and map() method, have different use cases and are not the most common choices for simple array iteration.
You're debugging a JavaScript application and notice that a function defined within an object method using an arrow function is not behaving as expected. The "this" keyword is not referring to the object. What could be the reason for this?
- Arrow functions always bind "this" to the object
- Arrow functions don't have their own "this"
- Objects cannot contain arrow functions
- The object's properties are incorrectly defined
Arrow functions in JavaScript do not have their own "this" context. Instead, they inherit the "this" value from their containing function or the global context. If an arrow function is used inside an object method, it will use the "this" from the surrounding scope, which might not be the object itself.
When using querySelectorAll, the returned object is a _______.
- NodeList
- HTMLCollection
- Array
- Element
When you use querySelectorAll, it returns a NodeList. A NodeList is a collection of DOM elements that match the specified selector. Unlike an HTMLCollection, a NodeList is not live, which means it won't change dynamically as the document does.
Which part of a "for" loop is executed only once, when the loop starts?
- Initialization
- Condition
- Increment
- Body of the loop
The part of a "for" loop that is executed only once, when the loop starts, is the initialization. It is where you define and initialize loop control variables. The condition is checked before each iteration, the increment is executed after each iteration, and the body of the loop contains the code that is executed repeatedly until the condition is false.
In order to make an object iterable with a for...of loop, you need to define its _______ method.
- loop
- forEach
- Symbol.iterator
- Object.iterable
To make an object iterable with a for...of loop, you need to define its Symbol.iterator method. This method should return an iterator object, which must have a next method that provides values one at a time. This enables you to use a for...of loop to iterate over the object's elements.