Selection Control Structures

Selection control structures are programming constructs that allow you to make decisions and execute different code blocks based on specific conditions. They play a crucial role in controlling the flow of execution in your Carbon programs.

if Statement

The if statement is the most basic selection control structure. It executes a block of code only if a specified condition is true.

Code snippet

var age: int = 25;

if age >= 18 {
  print("You are an adult.");
}

else Statement

The else statement can be combined with the if statement to provide an alternative block of code to execute if the condition in the if statement is false.

Code snippet

var age: int = 25;

if age >= 18 {
  print("You are an adult.");
} else {
  print("You are a minor.");
}

else if Statement

The else if statement allows you to check additional conditions if the previous if or else if conditions are false.

Code snippet

var grade: int = 85;

if grade >= 90 {
  print("Excellent!");
} else if grade >= 80 {
  print("Good job!");
} else {
  print("Needs improvement.");
}

switch Statement

The switch statement is a more concise way to handle multiple conditions. It compares a value against a set of cases and executes the corresponding code block.

Code snippet

var day: string = "Monday";

switch day {
case "Monday":
  print("It's Monday!")
case "Tuesday":
  print("It's Tuesday!")
default:
  print("It's another day!")
}

Nested Conditional Statements

You can nest conditional statements within each other to create more complex decision-making logic.

Code snippet

var age: int = 20;
var isStudent: bool = true;

if age >= 18 {
  if isStudent {
    print("You are an adult student.");
  } else {
    print("You are an adult non-student.");
  }
} else {
  print("You are a minor.");
}

Conditional Expressions

Carbon also supports conditional expressions, which allow you to evaluate a condition and return a value based on the result.

Code snippet

var message: string = age >= 18 ? "You are an adult." : "You are a minor.";

Selection control structures are essential for writing flexible and efficient Carbon programs. By understanding and using them effectively, you can create complex decision-making logic and control the flow of execution in your code.