lab - (7 of 17) Properties Versus Methods from Explorations

What is the primary purpose of a property in a Swift instance?

• To perform repeated actions on the instance.

• To provide or retrieve values specific to the instance.

• To manage side effects related to the instance.

• To execute complex logic using arguments.

Answer explanation

Correct Answer:
Explanation: A property provides a way to get or set a value that belongs to an instance. It does not perform additional work or require arguments.

What is the relationship between methods and properties in Swift?

• Methods refer to values, while properties provide behavior.

• Methods and properties are interchangeable in usage.

• Properties access values, while methods provide behavior specific to the instance.

• Properties handle side effects, while methods manage data retrieval.

Answer explanation

Correct Answer:
Explanation: Properties are used for accessing or setting values, while methods are for executing behavior or functionality tied to the instance.

Why does the removeAll() method qualify as a method instead of a property?

• It requires arguments to function.

• It involves side effects by modifying the instance.

• It retrieves a value without performing additional work.

• It is designed to calculate and return a value.

Answer explanation

Correct Answer:
Explanation: The removeAll() method modifies the instance (by emptying the string), which is considered a side effect, distinguishing it as a method.

Which of the following statements about methods and properties is true?

• Methods can take arguments, while properties cannot.

• Properties are designed to handle repeated actions.

• Methods and properties cannot be defined in custom types.

• Properties always involve additional computations.

Answer explanation

Correct Answer:
Explanation: Methods can accept arguments to perform specific tasks, whereas properties do not take arguments and are used solely for accessing or setting values.

Which scenario requires the use of a method rather than a property?

• Retrieving the current value of an instance variable.

• Performing an action that modifies the instance.

• Storing data to be used later in the app.

• Accessing a constant value shared across instances.

Answer explanation

Correct Answer:
Explanation: Methods are necessary for actions that modify the instance or require additional information, such as the removeAll() method that clears a string.

Which of the following best describes how apps typically use methods and properties?

• Apps rely mostly on global variables and functions instead of methods and properties.

• Most of the code in an app involves instance methods and properties on types.

• Properties are rarely used, and methods perform all instance-related tasks.

• Both methods and properties are defined only on predefined types, not custom types.

Answer explanation

Correct Answer:
Explanation: In app development, much of the code consists of instance methods and properties on types, often custom types, all working together to form the app’s functionality.

Why must hasPrefix() be a method instead of a property?

• It performs a calculation that retrieves an instance’s value.

• It modifies the instance by clearing its contents.

• It requires a prefix as an argument to perform its function.

• It accesses a constant value within the instance.

Answer explanation

Correct Answer:
Explanation: The hasPrefix() method needs a prefix argument to perform its check, making it a method rather than a property, as properties cannot take arguments.

What is a key difference between a property and a method?

• A property can execute complex actions, while a method retrieves values.

• A property provides or sets values, while a method performs actions, often with arguments.

• Properties and methods both execute side effects equally.

• Properties can be defined on types, but methods cannot.

Answer explanation

Correct Answer:
Explanation: Properties are for accessing or setting values, whereas methods perform actions, potentially involving arguments or side effects.