1. Iterative Constructs Review
What are named constants? Why are they needed?
What is a block? What is special about declaring a variable inside a block?
What is the difference between while and do-while? Can one replace the other?
what does for do? Why is it needed? what are the init-statement, expression, post-statement in a for? Can a for replace a while/do- while? is the reverse possible?
What is a loop variable? Where is it declared in a for? What is its scope?
how is break used inside a looping construct?
what is continue, how is it used?
what is a nested iterative construct? what is inner/outer loop? How many loops can be nested in C++?

2. Predefined Functions 2

3. Predefined Functions
C++ comes with libraries of code that can be used in your programs. The code comes in the form of pre-defined functions
what is the program that adds pre-defined functions to your code to produce the executable?
function name - identifier distinguishing the function from others; example the square root function is called: sqrt
argument - the value the function starts out with; a function may have more than one argument; an argument is an expression (thus, can be just a simple constant or variable);
return value - value computed by the function
the_root = sqrt(9.0);
function call (function invocation) - expression consisting of function name followed by arguments in parentheses
the function accepts arguments of a certain type and returns a value of certain type; sqrt accepts and returns double
to use a function you need to specify an include directive:
#include <cmath>
argument may be arbitrary expression including return value of a function
the_root = sqrt(myVar + 9.0); the_root = sqrt(abs(myVar));

4. Type Changing Functions
is there a problem with this code?
int a=9, b=2;
double c=a/b;
C++ provides functions for explicit conversions between types:
function double converts to type double:
double c=double(a)/b;
explicit type conversion is called type casting
warning: wrong application of casting:
double c=double(a/b);
note that type conversion may be implicit:
example:
int a=55;
double c = a + 30;
The integer expression is implicitly converted to double before assignment

5. Random Number Generation
(pseudo) random number generators are pre-defined functions that are used in programs to create events unpredictable by the user (e.g. events in games)
need to include <cstdlib>
creates a series of numbers, the numbers within the series are (pseudo) random
srand(SEED) – initializes the random number generator, needs to be invoked once in the program, no return value
SEED – selects the (pseudo) random series
rand() – returns a new integer random number in the series, can be used multiple times in program
the number is between 0 and RAND_MAX – a named constant predefined in <cstdlib>
idiom: to get a random number in a specific range, take a remainder of that range. Example, random number between 0 and 9 can be obtained as:
int myRandValue = rand() % 10;

6. Selecting Random Series with time()
time() – returns number of seconds since 01/01/1970, good for initializing unique series, needs <ctime>
selecting series
srand(1); - repeats series every time you run your program – good for debugging
srand(time()); - selects unpredictable series every time you run your program – good for final compilation
srand() rand() invocation
seed
time()