Class 4: C Storage Class, Scope Linkage

Question 1

Storage Class

Answer 1

Determines the type of storage and lifetime of storage associated with a variable and the variables initialization if any

Question 2

Storage scope

Answer 2

Determines which region of a program in which a variable can be accessed (by name and not through pointer)

Question 3

Linkage

Answer 3

Determines whether the same name in a different file frees to the same variables or function or some different variable function

Question 4

Stack

Answer 4

1. A place in memory where information specific to particular function is stored each time it is invoked
2. It is allocated when the function is called a deal located when he function returns

Question 5

Heap

Answer 5

1. A place in memory where information specific to a particular process is stored each time it is invoked
2. Any valuesstored here are available until the process stops executing

Question 6

Storage class

Answer 6

Refers to the type of memory in which a variable values is stored which defines different characteristics for variable

Question 7

Static (keyword)

Answer 7

The heap

Question 8

Automatic (keyword)

Answer 8

The runtime stack

Question 9

Register (keyword)

Answer 9

Hardware registers

Question 10

Do function identifiers have a storage class?

Answer 10

NO, they are not stored on the stack or the heap

Question 11

Storage Class: Static

Answer 11

Declared outside all blocks.
Retain the last value they were assigned until the program completes

Question 12

What value are storage class static variables automatically assigned to?

Answer 12

0

Question 13

Storage Class: Automatic

Answer 13

Declared inside a block.

Question 14

When are automatic variables created

Answer 14

Just before the execution of the code

Question 15

When are automatic variables discarded

Answer 15

When they are not longer accessible/ just as execution leaves the block

Question 16

What storage class do parameters of functions have????

Answer 16

AUTOMATIC

Question 17

Variable declared inside a block but with the keyword static

Answer 17

This changes storage class from automatic (the default) to static. Although this changes show long the variable exists during the program, IT DOES NOT CHANGE THE SCOPE STILL BLOCK SCOPE

Question 18

When keyword static is used within a block, it changes a variables ______

Answer 18

Storage class

Question 19

When the keyword static is used outside of any/all blocks, it changes an identifiers ________

Answer 19

Linkage

Question 20

Register variables

Answer 20

Stored in machines hardware registers rather than memory. Can be accessed faster. Created and destroyed at the same time as automatic variables

Question 21

Scope

Answer 21

Refers to the point in a program in which an identifier may be used to access a variable directly (not through pointer)

Question 22

Block scope

Answer 22

Variable can only be accessed within that block

Question 23

File scope

Answer 23

Declared outside fo all blocks. The identifier can be accessed anywhere from the end of its declaration to end of the source file in which it was declared

Question 24

Prototype scope

Answer 24

Only applies to parameter names DOES not apply to function names

Question 25

Any variables with prototype scope has no _____ or ______

Answer 25

Memory class, linkage This is because no memory has been allocated for the variable

Question 26

Void function2(int var3, int var4);

Answer 26

Function2 : file scope Var3: prototype scope Var4: prototype scope

Question 27

Void function1(int var1, int var2){}

Answer 27

Function1: file scope Var1: block scope Var2: block scope

Question 28

Linkage

Answer 28

Determines how many occurrences of a file scope identifier with the same name (in different files we plan to use together) are treated

Question 29

None linkage

Answer 29

Identifiers that have no linkage (variables without file scope). All block scope variables (NONE) and prototype scope variables (undefined)

Question 30

Internal linkage

Answer 30

All references to the file scope identifier within ONE source file

Question 31

External Linkage

Answer 31

All references to a file scope identifier in any source file refer to the entity

Question 32

What is default linkage of file scope variable?

Answer 32

External

Question 33

How can we change linkage of file scope variable from external to internal

Answer 33

Using the keyword static. This means that no programs except the .c file where the file scope variable is defined can access the variable

Question 35

Using a variable with external linkage in another .c file

Answer 35

If you want to use a variable with external linkage in another .c file, you DECLARE it using external. You cannot omit this declaration and use the variable directly.