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The switch statement

Learn multi-way selection with switch, case, break and default.

The switch statement

When a single variable is matched against several constant values, the switch statement is cleaner than an if/else if chain. The form is switch (x) { case 1: ...; break; case 2: ...; break; default: ...; }.

The code after each case label runs for that case; break exits the switch. Without break execution falls through to the next case. default runs when no case matches.

Fall-through without break

If you omit break inside a switch, execution continues to the next case. This is called fall-through. Sometimes the behavior is intentional: when several cases run the same code you list them on top of each other and put break only on the last one.

Most of the time, however, forgetting break is a bug; an unexpected case runs. Compilers usually warn about cases without break. Marking intentional fall-through with a comment is a good habit.

Practice Print the day name

The day variable is set to 2. Use switch (day) so that in case 2 the program prints "Tuesday". Add a break too.

Starter code

main.cpp
#include <iostream>

int main() {
    int day = 2;
    // Print the day name with switch
    return 0;
}

Sample solution

main.cpp
#include <iostream>

int main() {
    int day = 2;
    switch (day) {
        case 2:
            std::cout << "Tuesday" << std::endl;
            break;
    }
    return 0;
}

Expected output

Tuesday

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 Match each switch part to its role

Term Meaning
switch Starts the selection
case Case label
break Ends the branch
default When none match

2 Which keyword runs when no case matches in a switch?

main.cpp
switch (x) {
  case 1: ...; break;
  ...
}
  • case
  • break
  • default Correct answer
  • switch

Explanation: default runs when no case matches.

3 Write the break keyword

Question 
case 1: std::cout << "Monday";
    ____;
Answer 
case 1: std::cout << "Monday";
    break;

Explanation: break exits the switch. stop, exit and end are not switch keywords.

All lessons in Beginner

1 C++ basics

  1. What is C++?
  2. Your first program
  3. std::cout
  4. std::cin
  5. Comments
  6. Summary - C++ basics

2 Variables

  1. Declaring variables
  2. auto
  3. const
  4. constexpr
  5. Type conversion
  6. Summary - Variables

3 Data types

  1. Integer types
  2. Floating-point types
  3. bool and char
  4. std::string
  5. sizeof
  6. Summary - Data types

4 Project: Calculator

  1. Project design
  2. Add and subtract
  3. Multiply and divide
  4. Error handling
  5. Putting it together

5 Operators

  1. Arithmetic operators
  2. Assignment operators
  3. Comparison operators
  4. Logical operators
  5. Bitwise operators
  6. Summary - Operators

6 Strings

  1. std::string basics
  2. String concatenation
  3. String length
  4. Substring
  5. String search
  6. Summary - Strings

7 Conditionals

  1. The if statement
  2. else and else if
  3. The switch statement
  4. The ternary operator
  5. Nested conditionals
  6. Summary - Conditionals

8 Loops

  1. The for loop
  2. The while loop
  3. The do-while loop
  4. Range-based for
  5. break and continue
  6. Summary - Loops

9 Project: Shopping cart

  1. Cart design
  2. Adding products
  3. Calculating totals
  4. Listing the cart
  5. Putting it together

10 Arrays

  1. C-style arrays
  2. Array access
  3. std::array
  4. Multidimensional arrays
  5. Arrays and loops
  6. Summary - Arrays

11 std::vector

  1. Declaring vectors
  2. push_back
  3. size and at
  4. Vector access
  5. Vector loop
  6. Summary - std::vector

12 Functions

  1. Defining functions
  2. Return values
  3. Parameters
  4. Function overloading
  5. Default parameters
  6. Summary - Functions

13 References

  1. What is a reference?
  2. Declaring references
  3. Reference parameters
  4. const references
  5. Dangling references
  6. Summary - References

14 Pointer basics

  1. What is a pointer?
  2. The & address operator
  3. Pointer dereference
  4. nullptr
  5. Pointer arithmetic
  6. Summary - Pointer basics

15 Project: To-do CLI

  1. Task model
  2. Adding tasks
  3. Listing tasks
  4. Completing tasks
  5. Putting it together

16 Advanced string operations

  1. String streams
  2. stoi and stod
  3. to_string
  4. String comparison
  5. String modification
  6. Summary - Advanced strings

17 Structs

  1. Defining structs
  2. Using structs
  3. Struct and function
  4. Array of structs
  5. Nested structs
  6. Summary - Structs

18 Exception basics

  1. try/catch
  2. throw
  3. std::exception
  4. Custom exceptions
  5. catch all
  6. Summary - Exceptions

19 Namespaces

  1. Defining namespaces
  2. using
  3. std namespace
  4. Nested namespaces
  5. Namespace alias
  6. Summary - Namespaces

20 Beginner final

  1. Project design
  2. Data model
  3. Business logic
  4. Error handling
  5. Putting it together