7 Essential C++ Concepts for Every Developer
C++ is a powerful, high-performance programming language used in a wide range of applications, from game development to systems programming. To master C++, it’s crucial to understand some key concepts that form the foundation of this language. In this article, we will learn seven such essential C++ concepts that every developer should know.
Table of Content
- 1. Pointers
- 2. Object-Oriented Programming (OOP) Principles
- 3. Overloading
- 4. STL (Standard Template Library)
- 5. Memory Management
- 6. Exception Handling
- 7. Concurrency
1. Pointers
Pointers are one of the fundamental concepts in C++ which provides the lower-level memory access to the users. Memory addresses are stored in pointers, which are variables. They make direct memory manipulation possible, which is advantageous for operations like hardware access, dynamic memory allocation, and passing arguments by reference.
Example:
The below example demonstrates the use of pointers in C++.
// C++ program to demonstrate the use of pointers
#include <iostream>
using namespace std;
int main()
{
// define ab variable num
int num = 10;
// Pointer to int, storing the address of num
int* ptr = #
// Dereferencing ptr to get the value at that memory
// address
cout << "Value of num: " << *ptr << endl;
return 0;
}
Output
Value of num: 10
2. Object-Oriented Programming (OOP) Principles
C++ is an object-oriented programming language that lets us use classes and objects to model real-world entities that helps us to organize the complex programs into manageable and modular code. The following are the main OOP principles in C++:
- Classes and Objects: The classes are used to define the blueprint for objects (instance of a class).
- Encapsulation: Encapsulation is the wrapping up of data within single unit (called class).
- Inheritance: Inheritance is a mechanism that allows a class to inherit properties and behaviors from an existing class.
- Polymorphism: Polymorphism is an ability to process objects differently based on their data type or class.
These OOPs principles help us to create and maintain a large-scale application that may get more complex using other programming paradigms.
Example:
The below example demonstrates the principles of OOP in C++.
// C++ program to demonstrate OOP Principles
#include <iostream>
using namespace std;
// Define a base class named MyClass.
class MyClass {
public:
// Member function to print a message.
void myMethod()
{
cout << "Hello from MyClass!" << endl;
}
};
// Define a derived class named MyClass2 that inherits from
// MyClass.
class MyClass2 : public MyClass {
public:
// Member function to print a different message.
void myMethod2()
{
cout << "Hello from MyClass2" << endl;
}
};
int main()
{
// Create an object of MyClass.
MyClass obj;
// Create an object of MyClass2.
MyClass2 obj2;
// Call the myMethod() of MyClass using obj.
obj.myMethod();
// Call the myMethod2() of MyClass2 using obj2.
obj2.myMethod2();
// Call the myMethod() of MyClass using obj2.
obj2.myMethod();
return 0;
}
Output
Hello from MyClass! Hello from MyClass2 Hello from MyClass!
3. Overloading
C++ allows function and operator overloading that allows multiple definitions for the same function name or operator that can be differentiated using parameter types and number of parameters. It enhances code readability and reusability.
Example:
The below example demonstrates the overloading concept in C++.
// C++ program to demonstrate overloading
#include <iostream>
using namespace std;
// Define a class named Print.
class Print {
public:
// Member function to display an integer value.
void display(int i)
{
cout << "Integer: " << i << endl;
}
// Member function to display a double value.
void display(double d)
{
cout << "Double: " << d << endl;
}
};
int main()
{
// Create an object of the Print class.
Print obj;
// Call the display function with an integer argument.
obj.display(5);
// Call the display function with a double argument.
obj.display(10.5);
return 0;
}
Output
Integer: 5 Double: 10.5
4. STL (Standard Template Library)
The Standard Template Library(STL) is a powerful feature in C++ that provides a set of general purpose classes and functions for data structures and algorithms. In C++ STL provides the following:
- Containers: It is a collections of objects, such as vectors, lists, and maps.
- Iterators: Iterators are objects that point to elements within a container.
- Algorithms: These are functions for performing operations on containers, like sorting and searching.
Example:
The below example demonstrates the usage of container in C++ STL.
// C++ program to demonstrate container in STL
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
int main()
{
// Initialize a vector of integers with some values.
vector<int> nums = { 5, 2, 8, 1, 9 };
// Sort the vector in ascending order using the standard
// library sort function.
sort(nums.begin(), nums.end());
// Print the sorted vector elements.
cout << "Vector Elements: ";
for (auto it : nums) {
cout << it << " ";
}
cout << endl;
// Find and print the maximum element in the vector
// using the standard library max_element function.
cout << "Max element: "
<< *max_element(nums.begin(), nums.end()) << endl;
return 0;
}
Output
Vector Elements: 1 2 5 8 9 Max element: 9
5. Memory Management
C++ offers manual memory management via new, delete, malloc, and free methods for dynamic memory allocation and deallocation. Proper memory management is crucial to avoid memory leaks and dangling pointers. In C++ stack memory stores information about function calls and local variables. It is handled by the compiler automatically and heap memory must be explicitly handled by the programmer and is utilized for dynamic memory allocation. We also have smart pointer classes in C++({std::shared_ptr}, std::unique_ptr}, std::weak_ptr}) for automatic memory management.
Example:
The below example demonstrates the dynamic memory allocation and deallocation in C++.
// C++ program to demonstrate dynamic memory allocation and
// deallocation
#include <iostream>
using namespace std;
int main()
{
// Dynamic memory allocation
int* ptr = new int;
*ptr = 5;
// print he value of ptr
cout << "Value at ptr: " << *ptr << endl;
// Deallocate memory
delete ptr;
return 0;
}
Output
Value at ptr: 5
6. Exception Handling
Exception handling in C++ is a mechanism that enables elegant handling of anomalous situations and runtime faults to ensure the program can manage unexpected situations. C++ uses the try, throw and catch keywords to handle exceptions. Code in ‘try’ blocks has the potential to throw exceptions that are raised using `throw` instructions. and ‘catch’ blocks deal with exceptions thrown in the matching ‘try’ block.
Example:
The below example demonstrates the exception handling mechanism using try, throw and catch blocks
// C++ program to demonstrate exception handling
#include <iostream>
#include <stdexcept>
using namespace std;
int main()
{
try {
// Declare and initialize two integers.
int x = 10, y = 0;
// Check if the divisor is zero.
if (y == 0)
// Throw a runtime error exception if divisor is
// zero.
throw runtime_error("Divide by zero error");
// Perform division and print the result (this line
// won't execute if y is zero).
cout << "Result: " << x / y << endl;
}
catch (const runtime_error& e) {
// Catch the runtime error exception and print the
// error message.
cout << "Exception caught: " << e.what() << endl;
}
return 0;
}
Output
Exception caught: Divide by zero error
7. Concurrency
In C++, the concept of concurrency was first added in C++ 11 to improve the performance of the program and enable multitasking. Concurrency is the ability to carry out several tasks or threads at the same time. Within a process, threads are separate execution sequences that enable code to run in parallel. C++ uses a synchronization primitive called a mutex (mutual exclusion) is used to stop several threads from accessing shared resources at the same time
Example:
The below example demonstrates the basic overview of concurrency in C++.
// C++ program to demonstrate the concurrency
#include <iostream>
#include <thread>
using namespace std;
// Function to be executed by the new thread.
void threadFunction()
{
cout << "Hello from thread!" << endl;
}
int main()
{
// Create a new thread that runs the threadFunction.
thread t(threadFunction);
// Wait for the thread t to finish its execution.
t.join();
// Print a message from the main thread.
cout << "Main thread" << endl;
return 0;
}
Output
Hello from thread!
Main thread
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