Control Statements in C#

Control statements in C# manage the flow of execution in a program. They are divided into three main categories:

Selection Statements
Iteration Statements
Jump Statements

1. Selection Statements

Selection statements allow a program to choose different paths of execution based on conditions.

if…else

The if...else statement allows conditional execution of code blocks.

Example:

int number = 10;

if (number > 5)
{
    Console.WriteLine("The number is greater than 5.");
}
else
{
    Console.WriteLine("The number is 5 or less.");
}

switch…case

The switch...case statement allows selection among multiple options.

Example:

int day = 3;

switch (day)
{
    case 1:
        Console.WriteLine("Monday");
        break;
    case 2:
        Console.WriteLine("Tuesday");
        break;
    case 3:
        Console.WriteLine("Wednesday");
        break;
    default:
        Console.WriteLine("Another day");
        break;
}

2. Iteration Statements

Iteration statements allow a block of code to be executed repeatedly based on a condition.

while

The while loop executes a block of code as long as the condition is true.

Example:

int count = 1;

while (count <= 5)
{
    Console.WriteLine($"Count: {count}");
    count++;
}

do…while

The do...while loop is similar to while, but it guarantees at least one execution before checking the condition.

Example:

int count = 1;

do
{
    Console.WriteLine($"Count: {count}");
    count++;
} while (count <= 5);

for

The for loop provides a compact way to iterate with initialization, condition checking, and iteration expression all in one line.

Example:

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

The foreach loop in C# is used to iterate over elements in a collection (such as an array, list, or any enumerable object) without needing to manage the loop counter manually. It’s particularly useful when you want to iterate through all elements in a collection without modifying them.

Syntax:

foreach (var element in collection)
{
    // Code to execute for each element
}

Example:

string[] fruits = { "Apple", "Banana", "Cherry", "Date" };

foreach (string fruit in fruits)
{
    Console.WriteLine(fruit);
}

Explanation:

In the example above, the foreach loop iterates over each string in the fruits array.
The variable fruit takes on the value of each element in the array as the loop progresses.
The Console.WriteLine(fruit); statement prints each fruit name on a new line.

Output:

Apple
Banana
Cherry
Date

Use Cases:

Iterating Through Collections: foreach is perfect for iterating through elements in a collection, where you don’t need to modify the elements.
Read-Only Access: The loop variable in a foreach loop is read-only, ensuring that the collection elements aren’t inadvertently modified.
Simplifying Code: It reduces the complexity of managing loop counters and bounds checking.

3. Jump Statements

Jump statements transfer control to different parts of the program.

break

The break statement exits the loop or switch statement.

Example:

for (int i = 1; i <= 10; i++)
{
    if (i == 6)
    {
        break; // Exit the loop when i is 6
    }
    Console.WriteLine(i);
}

continue

The continue statement skips the current iteration of the loop and moves to the next iteration.

Example:

for (int i = 1; i <= 10; i++)
{
    if (i % 2 == 0)
    {
        continue; // Skip even numbers
    }
    Console.WriteLine(i);
}