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Putting it together

Build a working CLI app with a menu loop.

Putting it together

The final lesson is time to combine all pieces into a working app. The runMenu function takes a list of titles and calls addTask for each. This way the main program can add several tasks with a single call.

Signature: void runMenu(std::vector<Task>& tasks, const std::vector<std::string>& titles). In the body, use a range-based for to walk each title and call addTask(tasks, t). In main, declare a title list, then call runMenu and listTasks. This brings all the building blocks together.

Menu loop

The body of runMenu is a range-based for loop. This loop walks each element of the title vector in order and calls addTask. It is more readable than a classic index loop.

The syntax: for (const std::string& t : titles) { addTask(tasks, t); }. Here t takes one title each iteration; const and & pass it copy-free and read-only. This is the readable and efficient way modern C++ walks a range.

Practice The runMenu function

Define void runMenu(std::vector<Task>& tasks, const std::vector<std::string>& titles). In the body, use a range-based for to call addTask(tasks, t) for each title. In main, declare std::vector<std::string> titles = {"Ekmek al", "Süt al", "Yumurta al"};, then call runMenu(tasks, titles) and listTasks(tasks).

Starter code

main.cpp
#include <iostream>
#include <string>
#include <vector>

struct Task {
    std::string title;
    bool done;
};

void addTask(std::vector<Task>& tasks, const std::string& title) {
    Task t;
    t.title = title;
    t.done = false;
    tasks.push_back(t);
}

void listTasks(const std::vector<Task>& tasks) {
    for (size_t i = 0; i < tasks.size(); ++i) {
        if (tasks[i].done) {
            std::cout << "[x] " << tasks[i].title << "\n";
        } else {
            std::cout << "[ ] " << tasks[i].title << "\n";
        }
    }
}

void completeTask(std::vector<Task>& tasks, size_t index) {
    if (index < tasks.size()) {
        tasks[index].done = true;
    }
}

// Define the runMenu function

int main() {
    std::vector<Task> tasks;
    std::vector<std::string> titles = {"Ekmek al", "Süt al", "Yumurta al"};
    // Add runMenu and listTasks calls
    return 0;
}

Sample solution

main.cpp
#include <iostream>
#include <string>
#include <vector>

struct Task {
    std::string title;
    bool done;
};

void addTask(std::vector<Task>& tasks, const std::string& title) {
    Task t;
    t.title = title;
    t.done = false;
    tasks.push_back(t);
}

void listTasks(const std::vector<Task>& tasks) {
    for (size_t i = 0; i < tasks.size(); ++i) {
        if (tasks[i].done) {
            std::cout << "[x] " << tasks[i].title << "\n";
        } else {
            std::cout << "[ ] " << tasks[i].title << "\n";
        }
    }
}

void completeTask(std::vector<Task>& tasks, size_t index) {
    if (index < tasks.size()) {
        tasks[index].done = true;
    }
}

void runMenu(std::vector<Task>& tasks, const std::vector<std::string>& titles) {
    for (const std::string& t : titles) {
        addTask(tasks, t);
    }
}

int main() {
    std::vector<Task> tasks;
    std::vector<std::string> titles = {"Ekmek al", "Süt al", "Yumurta al"};
    runMenu(tasks, titles);
    listTasks(tasks);
    return 0;
}

Expected output

[ ] Ekmek al
[ ] Süt al
[ ] Yumurta al

Questions and answers

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

1 What is the first line of runMenu output?

main.cpp
std::vector<Task> tasks;
std::vector<std::string> titles = {"Ekmek al", "Süt al", "Yumurta al"};
runMenu(tasks, titles);
listTasks(tasks);
  • 1. Ekmek al
  • Ekmek al
  • [x] Ekmek al
  • [ ] Ekmek al Correct answer

Explanation: The first task is not done yet, so '[ ] Ekmek al' is printed.

2 Match each expression to its meaning

Term Meaning
void runMenu Function signature
for (const std::string& t : titles) Range-for
addTask(tasks, t) Add call
runMenu(tasks, titles) Call

3 runMenu body

Question 
for (const std::string& t : ____) { addTask(tasks, t); }
Answer 
for (const std::string& t : titles) { addTask(tasks, t); }

Explanation: for (const std::string& t : titles) walks the titles.

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