1. COMP102 – Programming Fundamentals I LA2B (Mon 5-7pm) LA2E (Fri 3-5pm) LA2F (Fri 5-7pm) TA: Jackie Lo

2. Lecture Review  Software Development Process Requirement analysis Specifications Design and architecture Coding Testing Documentation Maintenance

3. Lecture Review  Arithmetic Operators + - * /  Note: Precision problem int/int => int  Truncates instead of round-off  E.g. 3 / 2 => 1 % (modulus/remainder)  E.g. 10 % 3 => 1 int/double =>double double/int => double double/double => double

4. Lecture Review  Operator Precedence Evaluation order of operators  ( )  *, /  +, -  Left associativity Evaluate from left to right if same precedence E.g.  (1 + 2) * 3 – 4 / 5 1. 1 + 2 => 3 2. 3 * 3 => 9 3. 4 / 5 => 0 4. 9 – 0 => 9

5. Lecture Review  Assignment Statement Syntax  = ; E.g.  int a_var;  a_var = (1 + 2) * 3 – 4 / 5;

6. Lecture Review  Data Type Conversions Implicit  E.g. float z = 2.7; int y = 3; y = z;// y will be set to 2 Explicit  Syntax var_1 = type (var_2); var = type (expression);  E.g. int x = 1, y = 2; double z; z = x/y; // z will be set to 0.0 z = double (x)/double (y); // z will be set to 0.5 Now: 1.0 / 2.0 => 0.5 1 / 2 => 0

7. Lecture Review  Standard I/O Include the “ iostream.h ” Input  cin >> … Output  cout << …  Special output characters \a \t \n \\ \’ \”

8. Leeture Review  Format Manipulation Header Files  #include  using namespace std;

9. Lecture Review  Defining width Syntax  cout ); E.g.  cout <<setw(2) <<1.20 <<endl;  cout <<setw(7) <<123.00 <<endl;  Cout <<setw(7) <<1.20 <<endl;  Output: 1.20 123.00 1.20

10. Lecture Review  Defining sig. fig. Syntax  cout ); E.g.  cout <<setprecision(2) <<123.45 <<endl;  cout <<setprecision(4) <<101.0/4.0 <<endl;  Cout <<setprecision(4) <<1001.0/4.0 <<endl;  Output: 1.2e+02 25.25 250.3

11. More on prescision  How to define fixed decimal place? Syntax  cout.setf(ios::fixed);  cout ); E.g.  cout.setf(ios::fixed);  cout <<setprecision(2) <<123.45 <<endl;  cout <<setprecision(4) <<101.0/4.0 <<endl;  Cout <<setprecision(4) <<1001.0/4.0 <<endl;  Output: 123.45 25.2500 250.2500

12. Summary  By the end of this lab, you should be able to: Use arithmetic operators Evaluate expression with standard operator precedence order Write assignment Identify rules of division Apply assignment conversions Employ standard I/O functions  cin / cout

13. Lab2  Random a integer in a given range Syntax E.g.  Random [11-20) int rand_no; rand_no = rand()%(20-11)+11; #include int main() { srand(time(0)); int rand_no; rand_no = rand()%( - ) + ; }

14. Lab2  How about random no. with decimal place?  E.g. Random [11.0 – 20.0) int rand_no; double result; rand_no = rand()%(200-110)+110; result = rand_no * 0.1  E.g. Random [11.00 – 20.00) int rand_no; double result; rand_no = rand()%(2000-1100)+1100; result = rand_no * 0.01