Q
How can you ensure that a callback runs only once, even if the promise is resolved multiple times?

Answer & Solution

Answer: Option D
Solution:
The then() method ensures that a callback runs only once, even if the promise is resolved multiple times, by handling both success and failure cases appropriately.
Related Questions on Average

Which method allows you to specify multiple callbacks for different outcomes of a promise in jQuery?

A). done()

B). fail()

C). always()

D). then()

What does the promise() method return in jQuery?

A). A new deferred object

B). A new promise object

C). A new callback function

D). A new event handler

How can you handle errors in an asynchronous operation in jQuery?

A). Using the done() method

B). Using the fail() method

C). Using the always() method

D). Using the then() method

What is the purpose of the done() method in jQuery promises?

A). To handle failed operations

B). To handle completed operations

C). To handle pending operations

D). To create a new deferred object

What is event delegation in jQuery?

A). Attaching event handlers to dynamically created elements

B). Attaching event handlers to static elements

C). Attaching event handlers to parent elements

D). Attaching event handlers to all elements

How can you reject a deferred object in jQuery?

A). Using the reject() method

B). Using the resolve() method

C). Using the done() method

D). Using the always() method

What is a promise in jQuery?

A). An object that represents a completed task

B). An object that represents a pending task

C). An object that represents an asynchronous operation

D). An object that represents a synchronous operation

Which method is used to delegate an event handler in jQuery?

A). .on()

B). .delegate()

C). .bind()

D). .attach()

How do you attach multiple callbacks to a jQuery promise?

A). Using multiple then() methods

B). Using multiple done() methods

C). Using multiple fail() methods

D). Using multiple always() methods

What is a deferred object in jQuery?

A). An object that stores HTML elements

B). An object that represents a task that will finish in the future

C). An object that handles CSS styles

D). An object that manages event listeners