Iteration Control Structures

Iteration control structures are programming constructs that allow you to repeat code blocks multiple times. They are essential for performing repetitive tasks and processing data efficiently.

for Loop

The for loop is a simple and versatile iteration construct. It executes a block of code a specified number of times.

Code snippet

for i in 0...5 {
  print(i);
}

while Loop

The while loop continues to execute a block of code as long as a specified condition remains true.

Code snippet

var count: int = 0;
while count < 10 {
  print(count);
  count += 1;
}

do-while Loop

The do-while loop is similar to the while loop, but it guarantees that the code block is executed at least once before the condition is checked.  

Code snippet

var input: string = "";
do {
  print("Enter a number:");
  input = readLine();
} while input.isEmpty();

Nested Loops

You can nest loops within each other to perform more complex iterations.

Code snippet

for i in 0...3 {
  for j in 0...2 {
    print("i = \(i), j = \(j)");
  }
}

break and continue Statements

The break statement can be used to exit a loop prematurely. The continue statement can be used to skip the current iteration of a loop and proceed to the next iteration.

Code snippet

for i in 0...10 {
  if i == 5 {
    break; // Exits the loop
  }
  print(i);
}

for i in 0...5 {
  if i == 2 {
    continue; // Skips the current iteration
  }
  print(i);
}

Iterating Over Collections

Carbon provides convenient ways to iterate over collections like arrays and ranges.

Code snippet

var numbers: [int] = [1, 2, 3, 4, 5];

for number in numbers {
  print(number);
}

Iteration control structures are essential for writing efficient and concise Carbon programs. By understanding and using them effectively, you can perform repetitive tasks, process data, and create more powerful applications.