The 'switch' Statement

Part of the Fundamentals section of Coddy's Dart journey — lesson 36 of 94.

The switch statement in Dart offers a cleaner alternative to multiple if-else statements when checking a variable against different values.

void main() {
  String grade = 'B';
  
  switch (grade) {
    case 'A':
      print('Excellent performance!');
      break;
    case 'B':
      print('Good performance!');
      break;
    case 'C':
      print('Average performance.');
      break;
    case 'D':
      print('Below average performance.');
      break;
    default:
      print('Invalid grade.');
      break;
  }
}

When run, it outputs: Good performance!

Challenge

Easy

Create a program that determines a student's grade based on their exam score using a switch statement:

Declare an integer variable named examScore with a value of 85
Create a string variable named grade to store the letter grade
Use a switch statement with the following rules:

If examScore is between 90 and 100 (inclusive), set grade to "A"
If examScore is between 80 and 89 (inclusive), set grade to "B"
If examScore is between 70 and 79 (inclusive), set grade to "C"
If examScore is between 60 and 69 (inclusive), set grade to "D"
For any other score, set grade to "F"

Print the result in this exact format: Score: 85, Grade: B

Note: You'll need to use integer division to convert the score to a range that works with switch.

Cheat sheet

The switch statement in Dart provides a cleaner alternative to multiple if-else statements when checking a variable against different values.

switch (variable) {
  case 'value1':
    // code to execute
    break;
  case 'value2':
    // code to execute
    break;
  default:
    // code for unmatched cases
    break;
}

Each case must end with a break statement to prevent fall-through. The default case handles values that don't match any specific case.

String grade = 'B';

switch (grade) {
  case 'A':
    print('Excellent performance!');
    break;
  case 'B':
    print('Good performance!');
    break;
  default:
    print('Invalid grade.');
    break;
}

Try it yourself

void main() {
  // Declare the examScore variable here
  int examScore = 85;
  
  // Declare the grade variable here
  String grade;
  
  // Use a switch statement to determine the grade

  
  // Print the result
  print("Score: $examScore, Grade: $grade");
}