C Style Guide

Question 1

Keywords 1: Variable Definition

Answer 1

a quantity that may be changed according to the mathematical problem

int x;

Question 2

Keywords 2: Variable Declaration

Answer 2

x = 10;

Question 3

Keywords 3. Expressions

Answer 3

a combination of operands and operators

A+B;
A*B;
A==B:

Question 4

Keywords 4. Operators

Answer 4

+, -, *, /, %, ++, –,
Relational Operators: ==, !=, >, > >=, <=,

Logical Operators: &&, ||, !(A &&B)
https://www.tutorialspoint.com/cprogramming/c_operators.htm

Question 5

Keywords 5. Precedence table

Answer 5

https://www.cs.uic.edu/~i109/Notes/COperatorPrecedenceTable.pdf
operators will be performed in a different order of precedence, according to the precedence table.

Question 6

Keywords 6. Sequence points

Answer 6

https://learn.microsoft.com/en-us/cpp/c-language/c-sequence-points?view=msvc-170

A point where all of the previous expressions must have been completed before continueing with the following expressions

Question 7

Keywords 7. bits/bytes/wchar

Answer 7

wide char, meant to store UTF standard characters
bit, 1 and 0.
byte, 8 bits.

Question 8

Keywords 8. Binary/octal/hexadecimal/decimal

Answer 8

don’t make me do it

Question 9

Keywords 9. ASCII table

Answer 9

https://www.asciitable.com/

American Standard Code for Information Interchange,

Question 10

Keywords 10. UTF

Answer 10

Unicode Transformation Format.
UTF-8: 9bit unicode conversion format.
UTF 65 = A
UTF 66 = B
etc

Question 11

Keywords 11. Escape characters

Answer 11

backslash followed by uh, something.
https://www.ibm.com/docs/en/rdfi/9.6.0?topic=set-escape-sequences
\n creates a new line
\a creates an alert(?)
etc.

Question 12

Expressions:

Answer 12

; - separator
int a; variable definition
void foo(int); function declaration
if(a > b){/* . . . /}; flow control statement, (a>b is an expression)
return, continue, break, for, do and while; flow control statements
void bar(void){/ . . . /}; function definition
struct definition: X{/ . . . */}
Alias Definition: typedef struct X X_t

Question 13

Parts of Expressions

Answer 13

Type: int*, char, const, long, etc. including whether it is an l-value or non l-value
(l-value: expression representing a persistent memory location. can be accessed after the expression has been evaluated. & operator can only be used on l-value expressions)

Value: value of the expression

Side effect: something that can happen because of going through the expression at run time, but not needed in calculating the result.

Evaluation process: NOT a side effect.

Question 14

Examples of Expressions

Answer 14

85
integer literal, type: non l-value int, value: 85

‘a’
character literal. Type: non l-value int

“abc”
String literal. Type: l-value array of 4 characters. value: when converted to a char*, value is the address of the first character

x
Variable, Type: l-value expression of the type x, value: value that x was initialized or assigned to.

-Evaluation process:

Question 15

Sequence Points

Answer 15

Sequence Point: “A point in the code that guarentees the order of side effects”

Sequence Points: &&, ||, ? and ,
Sequence Point: ;

function call has two sequence points: one before it is called, and one after it returns. (must complete all side-effects preceding the parameter input, and return value.)

Question 16

Exercise 1: Given the following code snippet, fill in the following:
int a = 3;
int foo();
a. a

Answer 16

a
Type: int(l-value), Value: 3,

Question 17

Q1 Why are coding conventions important

Question 18

Q2 What is the difference between a declaration and a definition?

Question 19

Q3 Where will you find declarations? Definitions?

Question 20

Q4 What is the difference between unspecified and undefined?

Question 21

Q5 What does the following code do?
int main()
{
int x = 20, y = 35;
x = y++ + x++;
y = ++y + ++x;
printf(“%d%d”, x, y);
}

Question 22

Q6 What does the following code do?
a[i] = i++;

Question 23

Q7 Which operators create expressions with side effects?

Question 24

Q8 Why is this important?

Question 25

Q9 Where would you use the comma operator?

Question 26

Q10 Why are the operators arranged in that specific order in the precedence table?

Question 27

Q12 Will the following code compile? Will it run? Why?

Question 28

Q13 Find / create 5 confusing expressions, and confuse your colleagues and mentors.

Question 29

Q14 For each of these code snippets, is the bahaviour defined? Can you predict the order? Why?

Question 30

15 Count all the expresisons and sub-expressions in every example.
a-for each expression and sub-expression, identify its type, value, any side effects, evaluation process, and what could go wrong.
b. Compile and run the code snippers. Do they do what you expected?
c- Investigate implicit conversions and promotion rules for the last two snippers: