Introduction to Programming with C

Question 1

What kind of language is C described as in this lecture?

Answer 1

A high-level structured programming language often used for microcontroller applications.

Question 2

What three main things does this lecture focus on?

Answer 2

Good coding practices, C operators, and flow control structures.

Question 3

What are the main sections of the lecture?

Answer 3

C-language basics (formatting, comments, preprocessor, statements, variables, operators) and flow control (if, switch, while, for).

Question 4

Why is code formatting important?

Answer 4

It improves readability, maintainability, and makes programs easier to understand.

Question 5

Name three good code formatting practices.

Answer 5

Use descriptive names, indent nested code blocks, delete redundant code.

Question 6

What does “each function/class should have one purpose” mean?

Answer 6

Each function should do one clear job, not many unrelated things.

Question 7

Why is readability more important than cleverness in code?

Answer 7

Readable code is easier to debug, maintain, and understand by others.

Question 8

What is refactoring?

Answer 8

Rewriting existing code to improve structure and readability without changing behaviour.

Question 9

Why should you use version control and backups?

Answer 9

To keep track of changes and avoid losing work.

Question 10

What are comments in C used for?

Answer 10

To explain what the program or specific code blocks do, for future readers.

Question 11

Are comments compiled into machine code?

Answer 11

No, the compiler ignores comments.

Question 12

How do you write a multi-line comment in C?

Answer 12

Between /* and */.

Question 13

How do you write a single-line comment in C?

Answer 13

Start the line or part of the line with //.

Question 14

Give an example of a single-line comment in C.

Answer 14

A = 10; // This line sets variable A to 10

Question 15

What is the C pre-processor?

Answer 15

A tool that runs before compilation and processes lines starting with #.

Question 16

What does the #include directive do?

Answer 16

It includes the contents of a header file into the source file.

Question 17

How is #include used for system header files?

Answer 17

include <header_file.h></header_file.h>

Question 18

How is #include used for user-defined header files?

Answer 18

include “my_library.h”

Question 19

What does the #define directive do?

Answer 19

It defines a macro so that a name is replaced by a value or code snippet.

Question 20

Give an example of #define for a constant value.

Answer 20

define pi 3.1415

Question 21

Give an example of #define for a macro function.

Answer 21

define cube(x) (x) * (x) * (x)

Question 22

What is a statement in C?

Answer 22

A complete instruction ending with a semicolon.

Question 23

What are operators and operands?

Answer 23

Operators represent actions; operands are the data they act on.

Question 24

What is a function in C?

Answer 24

A block of code that can take inputs (arguments) and optionally return a value.

Question 25

What does the keyword void mean in a function declaration?

Answer 25

The function takes no arguments or returns no value (depending on position).

Question 26

What is a variable in C?

Answer 26

A name that refers to a memory address holding a value.

Question 27

Give an example of using variables to calculate a total.

Answer 27

num1 = 10; num2 = 20; total = num1 + num2;

Question 28

What are the main categories of operators listed in the lecture?

Answer 28

Data transfer, arithmetic, logical, bitwise logical, relational, program control.

Question 29

In C, how are most data transfer operations done?

Answer 29

Using assignment statements.

Question 30

Give a simple example of a data transfer sequence.

Answer 30

a = 10; b = 20; sum = a + b;

Question 31

What rule defines the order of arithmetic operations?

Answer 31

BODMAS or BIDMAS (brackets, orders, division/multiplication, addition/subtraction).

Question 32

List the basic arithmetic operators in C.

Answer 32

+, -, *, /, %, ++, --.

Question 33

What does the % operator do?

Answer 33

Gives the remainder (modulus) of integer division.

Question 34

What do ++ and -- do?

Answer 34

Increment and decrement a variable by 1.

Question 35

Why can brackets be useful in arithmetic expressions?

Answer 35

They clarify the intended order of operations and avoid mistakes.

Question 36

What happens if integer division is used, like 5 / 3 stored in an int?

Answer 36

It stores only the whole number part (e.g. 1).

Question 37

Why is 5.5 % 2 invalid in C?

Answer 37

The modulus operator % only works with integers.

Question 38

What is the result of 5.5 / 2 stored in a float?

Answer 38

2.75 (correct fractional result).

Question 39

What do logical operators return in C?

Answer 39

1 for true and 0 for false.

Question 40

What are the logical operators in C?

Answer 40

&& (and), || (or), ! (not).

Question 41

When is (A && B) true?

Answer 41

Only when both A and B are true.

Question 42

When is (A || B) true?

Answer 42

When at least one of A or B is true.

Question 43

What does !A do?

Answer 43

It flips the truth value of A (true becomes false, false becomes true).

Question 44

What do bitwise logical operators operate on?

Answer 44

Individual bits of the operands.

Question 45

List the bitwise logical operators in C.

Answer 45

&, |, ^, ~, <<, >>.

Question 46

What does & (bitwise AND) do?

Answer 46

Produces 1 in a bit position only if both bits are 1.

Question 47

What does | (bitwise OR) do?

Answer 47

Produces 1 in a bit position if either bit is 1.

Question 48

What does ^ (bitwise XOR) do?

Answer 48

Produces 1 in a bit position if the bits are different.

Question 49

What does ~ (bitwise NOT) do?

Answer 49

Inverts all bits (0 becomes 1, 1 becomes 0).

Question 50

What do << and >> do?

Answer 50

Left shift and right shift bits.

Question 51

Why are bitwise operators useful for I/O ports?

Answer 51

They allow setting, clearing, and toggling specific bits in port registers.

Question 52

How can XOR be used to toggle all bits of a port?

Answer 52

portA = portA ^ 0xFF;

Question 53

What are relational operators used for?

Answer 53

To compare values and produce a true or false result.

Question 54

List the relational operators in C.

Answer 54

==, !=, <, <=, >, >=.

Question 55

What does == mean in C?

Answer 55

Is equal to (comparison).

Question 56

What does = mean in C?

Answer 56

Assignment (store a value in a variable).

Question 57

What group of operators is “discussed in Section 3”?

Answer 57

Program control operators (flow control structures).

Question 58

What are flow control statements used for?

Answer 58

To control the order in which statements are executed.

Question 59

Which flow control structures are covered in the lecture?

Answer 59

if, if-else, if-elseif-else, switch, while, do-while, for, nested for.

Question 60

What does an if statement do?

Answer 60

Executes a block of code only if a condition is true.

Question 61

In C, what values are considered “true” in an if expression?

Answer 61

Any non-zero value.

Question 62

What is the basic form of an if statement in C?

Answer 62

if (expression) { statements; }

Question 63

What extra part does an if-else statement add?

Answer 63

An alternative block that runs if the condition is false.

Question 64

What does an if-elseif-else chain allow you to do?

Answer 64

Test multiple conditions in sequence and choose one of several blocks.

Question 65

Why might you use a switch statement instead of many if-else statements?

Answer 65

It can be clearer and easier to read when selecting between many constant cases.

Question 66

What are the “cases” in a switch statement?

Answer 66

The possible constant values that the expression might match.

Question 67

What is the default case in a switch statement?

Answer 67

The block that runs if none of the cases match.

Question 68

Why is break usually used inside each case?

Answer 68

To prevent fall-through to the next case.

Question 69

What type of values can case labels use?

Answer 69

Constant expressions such as numbers or characters.

Question 70

What does a while statement do?

Answer 70

Repeatedly executes a block as long as a condition is true.

Question 71

When is the condition tested in a while loop?

Answer 71

Before each iteration.

Question 72

How is a while loop written in C?

Answer 72

while (expression) { statements; }

Question 73

How is a do-while loop different from a while loop?

Answer 73

The condition is checked after the loop body, so it always runs at least once.

Question 74

How is a do-while loop written in C?

Answer 74

do { statements; } while (expression);

Question 75

What is a for loop used for?

Answer 75

Repeating a block of code a known number of times with a loop counter.

Question 76

What are the three parts of a for loop header?

Answer 76

Initialization, condition, increment.

Question 77

How is a typical for loop written in C?

Answer 77

for (init; condition; increment) { statements; }

Question 78

How can a for loop always be rewritten?

Answer 78

As an equivalent while loop.

Question 79

What is a nested for loop?

Answer 79

A for loop written inside another for loop.

Question 80

What can nested loops be used for?

Answer 80

Multi-dimensional counting or repeated operations, like minutes and seconds.

Question 81

What are the three main things summarised at the end of the lecture?

Answer 81

Clear coding and comments, operator categories, and C flow control statements with their flowchart representations.