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Summary - Conditionals

Combine if, switch and ternary to write a day-of-week app.

Summary - Conditionals

In this group you learned five constructs that make your program behave differently in different situations: if, else/else if, switch, ternary and nested conditionals.

Now you will combine them in a day-of-week app. First you will print the day name with switch, then check weekday vs weekend with if/else. Such combined tasks appear all the time in menus, clocks and state machines.

Practice Day name (switch)

The day variable is set to 3. Use switch (day) so that in case 3 the program prints "Wednesday". Add a break too.

Starter code

main.cpp
#include <iostream>

int main() {
    int day = 3;
    // Print the day name with switch
    return 0;
}

Sample solution

main.cpp
#include <iostream>

int main() {
    int day = 3;
    switch (day) {
        case 3:
            std::cout << "Wednesday" << std::endl;
            break;
    }
    return 0;
}

Expected output

Wednesday

Practice Weekend check (if/else)

The day variable is set to 6. Use the condition if (day == 6 || day == 7) to check the weekend; print "Weekend" when true and "Weekday" when false.

Starter code

main.cpp
#include <iostream>

int main() {
    int day = 6;
    // Weekend check with if/else
    return 0;
}

Sample solution

main.cpp
#include <iostream>

int main() {
    int day = 6;
    if (day == 6 || day == 7) {
        std::cout << "Weekend" << std::endl;
    } else {
        std::cout << "Weekday" << std::endl;
    }
    return 0;
}

Expected output

Weekend

Questions and answers

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

1 Match each construct to its scenario

Term Meaning
if (x > 0) Single condition check
if/else if/else Multiple ranges
switch (day) Constant value pick
(a > b) ? a : b One-line pick

2 Which construct does one-line conditional assignment?

main.cpp
// one-line pick
  • if/else
  • ternary (? :) Correct answer
  • switch
  • for loop

Explanation: The ? : operator yields a conditional value in one line.

3 Write the ternary symbol

Question 
int a = 7;
int b = 12;
int max = (a > b) ____ a : b;
Answer 
int a = 7;
int b = 12;
int max = (a > b) ? a : b;

Explanation: The ? operator picks the left value when the condition is true.

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