Control structures

Selection statements

if-else

• Accoladers niet nodig wanneer slechts 1 statement erin staat (ook zo bij alle iteratie structuren)
• docs

if (true) 
    Run(); 
else
    Stop();

bool Condition1 = true;
bool Condition2 = true;
bool Condition3 = true;
bool Condition4 = true;

if (Condition1) {
    // Condition1 is true.
}
else if (Condition2) {
    // Condition1 is false and Condition2 is true.
}
else if (Condition3) {
    if (Condition4) {
        // Condition1 and Condition2 are false. Condition3 and Condition4 are true.
    }
    else {
        // Condition1, Condition2, and Condition4 are false. Condition3 is true.
    }
}
else {
    // Condition1, Condition2, and Condition3 are false.
}

switch

• keywords case default when
• elke switch section moet een jump statement hebben: break continue goto return throw
• docs

Random rnd = new Random();
int caseSwitch = rnd.Next(1,4);

switch (caseSwitch) {
    case 1: // eerste switch section begint hier
        Console.WriteLine("Case 1");
        break; // jump statement
    case 2: // tweede switch section begint hier
    case 3: // de volgende twee statements gelden voor case 2 en 3 
        Console.WriteLine($"Case {caseSwitch}");
        goto case 1; // jump statement
    default: // derde switch section begint hier
        Console.WriteLine($"An unexpected value ({caseSwitch})");
        throw new NotImplementedException(); // jump statement
}

Voorbeeld van de when clause en van pattern matching.

public static double ComputeArea_Version3(object shape)
{
    switch (shape)
    {
        case Square s when s.Side == 0:
        case Circle c when c.Radius == 0:
            return 0;

        case Square s:
            return s.Side * s.Side;
        case Circle c:
            return c.Radius * c.Radius * Math.PI;
        default:
            throw new ArgumentException(
                message: "shape is not a recognized shape",
                paramName: nameof(shape));
    }
}

Iteration statements

for

for (int i = 1; i <= 5; i++)
{
    Console.WriteLine(i);
}

foreach

int[] fibarray = new int[] { 0, 1, 1, 2, 3, 5, 8, 13 };
foreach (int element in fibarray)
{
    Console.WriteLine(element);
}

while

int n = 1;
while (n < 6) 
{
    Console.WriteLine("Current value of n is {0}", n);
    n++;
}

do-while

int x = 0;
do 
{
    Console.WriteLine(x);
    x++;
} while (x < 5);