Lære Combining Conditions and Refactoring Nested Logic

When working with complex decision-making in Dart, you will often encounter situations where multiple conditions must be checked before executing a block of code. Instead of stacking several if statements inside one another, you can combine conditions using logical operators like && (and), || (or), and ! (not). This technique not only simplifies your code but also makes it easier to follow and maintain. Flattening deeply nested logic, sometimes called refactoring, involves rewriting code to reduce indentation and complexity, making your intentions clearer to anyone reading your code.

main.dart


              1234567891011121314151617181920212223242526272829303132
            
void main() {
  // Deeply nested logic (before refactoring)
  int age = 25;
  bool hasID = true;
  bool isMember = true;

  // Original nested logic
  if (age >= 18) {
    if (hasID) {
      if (isMember) {
        print("Access granted.");
      } else {
        print("Membership required.");
      }
    } else {
      print("ID required.");
    }
  } else {
    print("Must be at least 18 years old.");
  }

  // Refactored logic using combined conditions
  if (age >= 18 && hasID && isMember) {
    print("Access granted.");
  } else if (age < 18) {
    print("Must be at least 18 years old.");
  } else if (!hasID) {
    print("ID required.");
  } else if (!isMember) {
    print("Membership required.");
  }
}

By combining conditions with logical operators, you reduce the need for multiple levels of indentation and nested blocks. In the refactored example, the check for access is performed in a single line: if (age >= 18 && hasID && isMember). This approach makes it clear under which circumstances access is granted, and each subsequent else if cleanly handles the other possibilities. This style of refactoring improves readability, making it easier for you and others to understand the logic at a glance. It also enhances maintainability, since changes to the rules or conditions can be made in one place without having to untangle deeply nested code.

Var alt klart?

Tak for dine kommentarer!

Sektion 3. Kapitel 3

Spørg AI

Spørg om hvad som helst eller prøv et af de foreslåede spørgsmål for at starte vores chat

Suggested prompts:

Can you show an example of how to refactor nested if statements using logical operators?

What are some common mistakes to avoid when combining conditions in Dart?

Can you explain the difference between &&, ||, and ! in more detail?

Stryg for at vise menuen

main.dart


              1234567891011121314151617181920212223242526272829303132
            
void main() {
  // Deeply nested logic (before refactoring)
  int age = 25;
  bool hasID = true;
  bool isMember = true;

  // Original nested logic
  if (age >= 18) {
    if (hasID) {
      if (isMember) {
        print("Access granted.");
      } else {
        print("Membership required.");
      }
    } else {
      print("ID required.");
    }
  } else {
    print("Must be at least 18 years old.");
  }

  // Refactored logic using combined conditions
  if (age >= 18 && hasID && isMember) {
    print("Access granted.");
  } else if (age < 18) {
    print("Must be at least 18 years old.");
  } else if (!hasID) {
    print("ID required.");
  } else if (!isMember) {
    print("Membership required.");
  }
}

Var alt klart?

Tak for dine kommentarer!

Sektion 3. Kapitel 3