If-Else

• If statements are condiitional statements and use booleans to enter the statement

int temperature = 100;

if (temperature >= 90)
{
    System.out.println("It is hot");
}

It is hot

• If-else statments execute a block of code if the condition is true, but another if the condition is false

int temperature = 86;

if (temperature >= 90)
{
    System.out.println("It is hot");
}

else
{
    System.out.println("It is cold");
}

It is cold

• If-elseif-else statements provide multiple conditions of else if statements in addition to the else statement

int temperature = 65;

if (temperature >= 90)
{
    System.out.println("It is hot");
}

else if ((60 < temperature) && (temperature < 90))
{
    System.out.println("It is warm");
}

else
{
    System.out.println("It is cold");
}

It is warm

Switch Case

double drivingAge = 15;
double permitAge = 15.5;
if (drivingAge >= 16)
{
    System.out.println("You can drive");
}
else if (drivingAge >= 15.5)
{
    System.out.println("You can get your permit");
}
else if ((drivingAge < 16) && (permitAge < 15.5))
{
    System.out.println("You are too young to drive");
}
else if ((drivingAge < 16) && (permitAge >= 15.5))
{
    System.out.println("You can drive with a parent");
}
else 
{
    System.out.println("Stay off the streets");
}

You can drive with a parent

int drivingAge = 16;

switch(drivingAge)
{
    case 0:
    System.out.println("You were just born");
    break;

    case 15:
    System.out.println("You can get your permit");
    break;

    case 16:
    System.out.println("You can get your license");
    break;

    case 18:
    System.out.println("You can get a vertical license");
    break;

    case 100:
    System.out.println("This seems a little dangerous to be driving");
    break;

    default:
    System.out.println("I'm not sure");
    break;
}

You can get your license

De Morgans Law

• De Morgans law lits multiple conditions that need to be met to enter the code block
• Uses the operands AND, OR and NOT and two input variables, A and B

boolean a = true;
boolean b = false;
if (a) {
    System.out.println("True code block");
}

if (a && !b) {
    System.out.println("True code block");
}

if (a || b) {
    System.out.println("True or False code block");
}

if ((a && !b) && (a || a)) {
    System.out.println("true or false");
}

if (!a && b ) {
    System.out.println("False code block");
}

True code block
True code block
True or False code block
true or false