1. Introduction to C++ Programming Language
Jeon, Seokhee Assistant Professor
Department of Computer Engineering, Kyung Hee University, Korea

2. About The Lecture Note
This lecture note is intended to be used by students in “Introduction to C++ Programming Language” course at the Kyung Hee University.
Originally made by Professor Sungwon Lee for the same course, but slightly modified by me.
The slides are mainly based on the class textbook, “Computer Science : A Structured Approach Using C++, 2nd Edition”

3. CH.3 EXPRESSIONS, OPERATORS, STATEMENTS

4. Expressions 2 + 5 Operand Expression Operator
A sequence of operands and operators that reduces to a single value
Example:
Operand
2 + 5
Expression
Operator

5. C++ Expression Format
Just look, and don’t remember! We will see specific examples.

6. Primary Expressions
Three types of primary expressions

7. Binary Expressions

8. Binary Expression -- Multiplicative Expressions
10 * 12
20 / 4
5 % 2 ???
Modulus Operator (%) (나머지 연산)
5 % 2  1
5 % 3  2
6 % 3  0

9. Binary Expression -- Additive Expressions -- Sample Codes
3 + 5, 4 – 6

10. Assignment expressions
The assignment expression has a value and a result.
The value of the total expression is the value of the expression on the right of the assignment operator (=).
The result places the expression value in the operator on the left of the assignment operator.
The left operand in an assignment expression must be a single variable.

11. Simple Assignment
Consists of simple algebraic expressions
Examples

12. Compound Assignment Shorthand notation for a simple assignment
Examples

13. Sample Code for Assignment Expression

14. Postfix Expressions Remember! (a++) is (a = a + 1)

15. 5) Unary expressions Remember! (++a) is (a = a + 1)

16. Example code reading (Program 3-4)
#include <iostream>
#include <iomanip>
using namespace std;
int main () {
int a = 4;
cout << "value of a : " << setw(2) << a << endl;
cout << "value of ++a : " << setw(2) << ++a << endl;
cout << "new value of a: " << setw(2) << a << endl;
return 0;
} // main
value of a : 4
value of ++a : 5
new value of a: 5

17. Operator Precedence Which operator will be evaluated first?
Each operator has one of 18 precedence levels
Look at the cover page of the book

18. Operator Precedence Examples
2 + 3 * 4
( 2 + ( 3 * 4) )
-b++
( -( b++ ) )

19. Operator Associativity
Determine the evaluation order of the operators having the same precedence
Left associativity vs. Right associativity

20. Operator Associativity Examples
Left associativity
Right associativity

22. Statements
A block of instructions
Types of statements

23. Expression Statements
Examples
a = 2;
a = b = 3;
a = 4 + 5;
a = b + (45 / c) + 22;
a++;
* An expression statement is terminated with a semicolon (;). The semicolon is a terminator, and it tells the compiler that the statement is finished.

24. Compound Statements
A block of multiple statements