C++ Part 18

A SINGLE STATEMENT FOR EACH ALTERNATIVE

if (Boolean_Expression) Yes_Statement else No_Statement If the Boolean_Expression evaluates to true, then the Yes_Statement is executed. If the Boolean_Expression evaluates to false, then the No_Statement is executed.

Multi if-else Statement

if (Boolean_Expression_1) Statement_1 else if (Boolean_Expression_2) Statement_2 . . . else if (Boolean_Expression_n) Statement_n else Statement_For_All_Other_Possibilities // EXAMPLE if ((temperature < -10) && (day == SUNDAY)) cout << "Stay home."; else if (temperature < -10) // and day != SUNDAY cout << "Stay home, but call work."; else if (temperature <= 0) // and temperature >= -10 cout << "Dress warm."; else // temperature > 0 cout << "Work hard and play hard.";

Intro to C++ Part 12

• How Do I Start a Program? 

1.  Identify inputs and outputs.
2. Understand what you asked for ( Ask Questions ).
3. Break the program down. // Functions
4. into steps, writing each step in pseudocode English.
5.  Replace each pseudocode step with C++ codes.

Intro to C++ Part 10

Expression 

The following table is showing some example and the equivalent meaning ones:

EXAMPLE	EQUIVALENT TO
count += 2;	count = count + 2;
total -= discount;	total = total - discount;
bonus *= 2;	bonus = bonus * 2;
change %= 100;	change = change % 100;
amount *= cnt1 + cnt2;	amount = amount * (cnt1 + cnt2);

Intro to C++ Part 9

A statement

is an instruction that is executed and typically
updates some variable (called a side effect).
An expression is something that is evaluated and does not update
a variable (typically)
int x,y;
y=5;
x = (y = y+2);

What is x going to be?

Evaluate 5+2 and store 7 in y
2 Above also resulted in evaluating the y=y+2 expression, to 7.
→ store 7 in x.

It is very bad Idia to do so

Assignment Statements
In an assignment statement, first the expression on the right-hand side of the equal sign is
evaluated and then the variable on the left-hand side of the equal sign is set equal to this value.
SYNTAX
Variable = Expression;
EXAMPLES
distance = rate * time;
count = count + 2;