IF STATEMENTS

syntax

if statement:
    if (logical expression)
        statement

if else statement:
    if (logical expression)
        statement
    else
        statement

    A logical expression is an expression that evaluates to be either true or false
    statement - is a single statement or a compound statement
    a compound statement is is a block of statements enclosed in curly braces

example of a compound if statement:
    if (logical expression)
    {
        statement1
        statement2
        ...
        statement n
    }

All n statements will execute if the logical expression is true and not execute if the logical
expression is false.

Keep in mind that a statement could be another if statement.  This would be called a nested
if statement

many scenarios arise (listed are just a few)

    if (logical expression)
        if (logical expression)
            statement


    if (logical expression)
        statement
    else
        if (logical expression)
            statement


    if (logical expression)
    {
        statement1
        statement2
        if (logical expression)
        {
            statement1
            statement2
        {
        else
            statement
    }
    else
        if (logical expression)
            statement


SWITCH STATEMENT

We use a switch statement when we have a number of specific alternatives to choose from.

syntax

    switch ( expression)
    {
        case value1:    statements
                               break;
        case value2:     statements
                                break;
        .
        .
        .
        case value n:    statements
                                break;
        default:    statements
    }

Some important things to note about switch statements:
    the expression can only be of an integral type
    each valuei must be an integral constant or a literal
    the break statement will cause you to exit the switch statement (jump down to the point following
    the ending }.  If you forget a break you will drop down into the next case and execute that
    code.


example switch statement

let x, y and z be in int variables previously declared

switch (x)
{
    case 1:    cout << y << " + " << z << " = " << y + z << endl;
                  break;
    case 2:    cout << y << " - " << z << " = " << y - z << endl;
                   break;
    case 3:    cout << y << " * " << z << " = " << y * z << endl;
                   break;
    case 4:     if (z == 0)
                        cout << "Cannot divide as denominator is 0" << endl;
                   else
                         cout << y << " / " << z << " = " << y / z << endl;
                   break;
    default:    cout << "you did not make a valid selection" << endl;
}

if x has the value of 1, case 1 will execute
if x has the value of 2, case 2 will execute
if x has the value of 3, case 3 will execute
if x has the value of 4, case 4 will execute
if x has another value, the default case will execute