variables and assignment, cout

int x = 5;
int y = 7, z = 9;
cout << x << ' ' << y ' ' << z << endl;
x = y; y = z; z = x;
cout << x << ' ' << y ' ' << z << endl;
x = y; y = z; z = x;
cout << x << ' ' << y ' ' << z << endl;

arithmetic

int x = 5, y = 2, z = 3;
cout << x * y + z << endl;
cout << x * y / y / x << endl;
cout << x / z << ' ' << x % z << endl;
cout << y / z << ' ' << y % z << endl;
cout << x - y * z - x << endl;

cin

int x = 5, y = 2, z = 3;
cin >> x >> y >> z;				// NO endl
cout << x << ' ' << y << ' ' << z << endl;

simple graphics

(0, 0) to (200, 200) or to (400, 400)
verbs:	Frame, Paint, Erase, Invert
objects:	Rect, Oval, Circle
Also:  MoveTo, LineTo, DrawLine, ShowText
SetForeColor(red, green, blue);

for, while, do .. while

for (int N = 1; N <= 15; N += 3)
	cout << N <<" "<< N / 2 << endl;

Write a loop with this output:
1 2 4 8 16 32 64

int x = 1;
int y = 1;
while (x < 200){
	cout << x << "   " << y << endl;
	x = 2*x;
	y = y + x;
}

x = 100;
do {
	cout << x << endl;
	x /= 3;
} while (x > 1)

if, if else

int x = 100;
if (x % 9 == 1) cout << "OK" << endl;
if (x % 9 == 3) 
	x = x - 11;
else
	x = x + 4;
cout << x << endl;


cout << "enter x:  ";
cin >> x;						// try 100, 72, 35
if (x % 5 == 0)
	if (x % 10 == 0)
		cout << "divisible by 10" << endl;
else
	cout << "not divisible by 5" << endl;

logical operators

	and &&		or ||  		not !
	equals ==		<	<=	>	>=	!=
(3 < 5) or (7 < 2)
(3 < 5) and (7 < 2)

Write a C++ logical expression for each of the following:

• x is between 2y and 3y
• N is divisible by 10 but not by 5
• x is the highest integral power of 2 less than y

switch

Simple Functions - Flow of Control

// function prototype
void somestuff();
void otherstuff();

main()
{
	somestuff();
	cout << "Now is the time" << endl;
	otherstuff();
	cout << "For all good dogs" << endl;
	otherstuff();
	somestuff();
	cout << "To find their bones." << endl;
}

void somestuff()
{
	cout << "+=+=+=+" << endl;
}

void otherstuff()
{
	for (int K = 0; K < 6; K++)
		cout << K << ' ' << " *** ";
	cout << endl;
}

Functions

int x = 2; y = 9;
while (x < y) 
	x = F(x, y);
xout << x << ' ' << y << endl;

int F(int x, int y){
	if (x < y)
		return 2*x;	
	else
		return 2*y;;	
}

These are the functions from the Little Function Lab. You should be able to write them.

1. the distance function
2. the factorial function
3. the min function
4. the Money function
5. the IsSquare function
6. the IsLetter function
7. the Roll function

1. CircleArea - argument radius, returns the area
2. CircleCircumference - argument radius, returns the circumference
3. RectArea - arguments height and width returns the area
4. CircleFits arguments, x, y, r, returns true if fits in small window
5. IsVowel char argument, true if char is a vowel
6. IsPrime returns true iff int argument is prime
7. argument a string, returns the number of words // assume only letters and blanks
8. IsOp returns true iff the char argument is '+', '-', '*', ore '/'

Arrays

int A[8] = { 3, 5, 4, 2, -1, 7, 0, 6 };

void WriteArray(int A[], int N){
	for (int J = 0; J < N; J++)
		cout << J << ' ' << A[J] << endl;
	cout <<, endl;
}

for (int J = 0; J < 8; J++)
	if (A[J] < 1) A[J] = 1;
WriteArray(A, 8);

for (int J = 0; J < 7; J++)
	A[J] += A[J+1];
WriteArray(A, 8);

for (int J = 0; J < 8; J++)
	A[J] = A[(J*J) % 8];
WriteArray(A, 8);

Other Stuff