variable = expression type name; int x;x____________________ int y;y____________________ int...
TRANSCRIPT
variable = expression
type name;int x; x____________________int y; y____________________int z; z____________________
variable = expression
type name;int x; x______________3_____int y; y____________________int z; z____________________
X = 3
variable = expression
type name;int x; x______________3_____int y; y____________________int z; z____________________variable = expressionX = 33 = x;X + y = 3;
Constant
const float PI = 3.141517;float j;j = PI;const float MD_TAX_RATE = .06;salesTax= price * MD_TAX_RATE;const string UNIV_NAME = “Towson University”;
taxRate = MD_TAX_RATE;
name = “Joe”; name ‘J’, ‘o’, ‘e’_______________name = Joe; //incorrect
variable = expression
Expression can be a constant:x = 3;taxrate = MD_TAX_RATE;
Or:expression can be a combination of
variables, constants, operators
int x; x ___________10__int y;int z;x = 10;
int x; x ___________10__=> 11int y;int z;x = x + 1;
int x; x ___________11int y; y ___________12int z;x = x + 1;y = x + 1;x+1
int x; x ___________11int y; y ___________12int z; z_____________x = x + 1;INCREMENT -numStudents=numStudents+1;++x;
int x; x ___________11int y; y ___________12int z; z___________6_z = 6;++z; or z = z + 1; => z is 7
numWidget = 10;stuff
name
widget
numWidgets 10
numWidgets = numWidgets + 1;stuff
name
widget
numWidgets 11
name = “Toby”;stuff
name ‘T’ | ‘o’ | ‘b’ |’y’ | NULL
widget
numWidgets 11
name = “Toby”;stuff
name ‘T’, ‘o’, ‘b’,’y’, NULL
widget
numWidgets 11
stuff = numWidgets;stuff 11
name ‘T’, ‘o’, ‘b’,’y’, NULL
widget
numWidgets 11
widget = numWidgets*2;stuff 11
name ‘T’, ‘o’, ‘b’,’y’, NULL
widget
numWidgets 11
int stamp;variable = expressionstamp = 14;14 = stamp; //invalid14 = x; //invalid2 + x= 14; //invalid
+
salesTaxitemPricetotalPricetotalPrice = itemPrice + salesTax;
-
x = x-1; //DECREMENT--x;
grossPaynetPaytaxnetPay= grossPay – tax;
division /
10/3 => 3cout << 10/3;10/3integer/integer integer division10/3 => 30/1 => 00/1.0 => .5 (float division)
int test1;int test2;float avg;avg = (test1+test2)/2;coercionavg = (float)(test1+test2)/2;
Modulus %
Remainder10 % 5 => 0 25 |10 10 0 remainder
%
8 % 2 => 095 % 2 => 1138 % 2 => 0Useful for determining even numbersnum % 2 If (num %2 == 0) //even number
PEMDAS
• Please• Excuse• My Dear• Aunt Sally
avg = test1 + test2/2;What is wrong?Division has higher precedencetest2/2 happens firstavg = (test1 + test2)/2;
y = x * 3 – z + 5 * a ^ 2;y = x * 3 – z + 5 * (a ^ 2);y = (x * 3) – z + 5 * (a ^ 2);y = (x * 3) – z + (5 * (a ^ 2));y = ((x * 3) – z) + (5 * (a ^ 2));
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
int main(){ int num1; int num2; int num3; int sum;
Step 1. Declare the variables
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
int main(){ int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
Step 2. write code for each processing step
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
int main(){ int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
Step 2. write code for each processing step
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
int main(){ int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << sum;
Step 2. write code for each processing step
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
int main(){ int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << “sum is “” << sum;
Step 2. write code for each processing step
Input
Processing
Output
num1
Input num1, num2, num3
sum
num2
Calculate sum
num3
Display sum
int main(){ int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3; //echo the input cout << num1 << “ + “ << num2 << “ + “ << num3 << “ = “ << sum << endl;
Step 2. write code for each processing step
TRACE1. write the variables across the top of the page
num1 num2 num3 sum Output
int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << num1 << “ + “ << num2 << “ + “ << num3 << “ = “ << sum << endl;
TRACE2. run each line
num1 num2 num3 sum OutputEnter two numbers
int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << num1 << “ + “ << num2 << “ + “ << num3 << “ = “ << sum << endl;
TRACE2. run each line
num1 num2 num3 sum Output1 2 3 Enter two numbers
int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << num1 << “ + “ << num2 << “ + “ << num3 << “ = “ << sum << endl;
TRACE2. run each line
num1 num2 num3 sum Output1 2 3 6 Enter two numbers
int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << num1 << “ + “ << num2 << “ + “ << num3 << “ = “ << sum << endl;
TRACE2. run each line
num1 num2 num3 sum Output1 2 3 6 Enter two numbers
1 + 2 + 3 = 6
int num1; int num2; int num3; int sum;
cout << “Enter two numbers “ << endl; cin >> num1 >> num2 >> num3;
sum = num1 + num2 + num3;
cout << num1 << “ + “ << num2 << “ + “ << num3 << “ = “ << sum << endl;
Write a program to input the price of an item, the sales tax rate and calculate the total price
.
Input Process Output
itemPrice Input itemPrice, salesTaxRate totalPrice
salesTaxrate Calculate totalPrice
Display totalPrice
Write a program to input the price of an item, the sales tax rate and calculate the total price
.
Input Process Output
itemPrice Input itemPrice, salesTaxRate totalPrice
salesTaxrate Calculate totalPrice
Display totalPrice
float itemPrice;float salesTaxRatefloat totalPrice;
Write a program to input the price of an item, the sales tax rate and calculate the total price
.
Input Process Output
itemPrice Input itemPrice, salesTaxRate totalPrice
salesTaxrate Calculate totalPrice
Display totalPrice
float itemPrice;float salesTaxRatefloat totalPrice;
cout << “Enter item price” << endl;cin >> itemPrice;cout << “enter sales tax rate “ <<endl;cin >> salesTaxRate;
Write a program to input the price of an item, the sales tax rate and calculate the total price
.
Input Process Output
itemPrice Input itemPrice, salesTaxRate totalPrice
salesTaxrate Calculate totalPrice
Display totalPrice
float itemPrice;float salesTaxRatefloat totalPrice;float salesTaxRate;
cout << “Enter item price” << endl;cin >> itemPrice;cout << “enter sales tax rate “ <<endl;cin >> salesTaxRate;
salesTax = itemPrice * salesTaxRate;totalPrice = itemPrice + salesTax;
Write a program to input the price of an item, the sales tax rate and calculate the total price
.
Input Process Output
itemPrice Input itemPrice, salesTaxRate totalPrice
salesTaxrate Calculate totalPrice
Display totalPrice
float itemPrice;float salesTaxRatefloat totalPrice;float salesTaxRate;
cout << “Enter item price” << endl;cin >> itemPrice;cout << “enter sales tax rate “ <<endl;cin >> salesTaxRate;
salesTax = itemPrice * salesTaxRate;totalPrice = itemPrice + salesTax;Cout << “item price is “ << itemPrice << “ sales tax rate is “ …