Chapter 5

Question 1

What are the design issues related to names?

Answer 1

• Length
• Connector characters
• Case sensitivity
• Reserved words or keywords
• Some languages require the use of special characters to start their variables

Question 2

What is the sextuple of attributes for a variable?

Answer 2

• Name
• Address
• Value
• Type
• Scope
• Lifetime

Question 3

When considering the address of a variable, what is an alias?

Answer 3

Multiple names for the same address.

Question 4

What are the two broad categories of binding?

Answer 4

• Static binding: Permanent assignment of an address during the execution of a program
• Dynamic binding: The address can change during execution

Question 5

What is scope?

Answer 5

Where it is legal to reference a variable.

Question 6

What is lifetime?

Answer 6

How long a variable exists in memory.

Question 7

How is static scope used to determine the value of a variable?

Answer 7

The value of the variable is determined prior to execution.

Question 8

How is dynamic scope used to determine the value of a variable?

Answer 8

The value is determined by subsequent function calls during runtime.

Question 9

What is a referencing environment and how is it used to determine the value of a variable?

Answer 9

The combination of all of the names that are in scope at the point in the code where a name is used.