Switch Case in Dart

In Dart, switch-case statements are a great tool for managing multiple conditions in a clean and organized way. They serve as a more efficient alternative to lengthy if-else chains, making your code easier to read and maintain.

Syntax:

switch (expression) { 
  case value1:  
    // Body of value1
    break; 

  case value2:  
    // Body of value2 
    break; 

  // Add more cases as needed

  default:  
    // Body of default case  
    break; 
}

The default case is the case whose body is executed if none of the above cases matches the condition.

Rules to follow in switch case:

• There can be any number of cases. But values should not be repeated.
• The case statements can include only constants. It should not be a variable or an expression.
• There should be a flow control i.e. break within cases. If it is omitted then it will show an error.
• The default case is optional.
• The nested switch is also there thus you can have a switch inside the switch.

Normal switch-case statement

Example:

void main()
{
        int gfg = 1;
        switch (gfg)
        {
            case 1: {
                print("GeeksforGeeks number 1");
            }
            break;
            case 2: {
                print("GeeksforGeeks number 2");
            }
            break;
            case 3: {
                print("GeeksforGeeks number 3");
            }
            break;
            default: {
                print("This is default case");
            }
            break;
        }
}

Output:

GeeksforGeeks number 1

Nested switch-case statement

Example:

void main()
{
    int gfg1 = 1;
    String gfg2 = "Geek";
    switch (gfg1) {
        case 1: {
            switch (gfg2) {
                case 'Geek': {
                    print("Welcome to GeeksforGeeks");
                }
            }
        } 
        break;
        
        case 2: {
            print("GeeksforGeeks number 2");
        } 
        break;
        
        
        default: {
            print("This is default case");
        } break;
    }
}

Output:

Welcome to GeeksforGeeks

Conclusion

Switch-case statements in Dart offer a handy way to manage multiple constant conditions, making them a great alternative to lengthy if-else chains. One key difference is that switch statements focus solely on compile-time constants. While it's not always necessary to include a break statement, skipping it can lead to some unexpected behavior, as it allows the program to "fall through" to the next case. You can also add a default case to catch any conditions that don't match the others. Interestingly, Dart supports nested switch-case statements too, although they're not used as often.