C++ Programming Language Tutorial
Overview
C++ is a high-level programming language that includes object-oriented, procedural, and generic programming features. It is widely used for system/software development, game development, and performance-critical applications.
Basic Syntax
Hello World
A simple program to print "Hello, World!" to the console.
Comments
- Single-line comment:
// This is a single-line comment - Multi-line comment:
Data Types
Primitive Data Types
- int: Integer type
- float: Floating-point type
- double: Double precision floating-point type
- char: Character type
- bool: Boolean type
Example
#include <iostream>
int main() {
int age = 25;
float height = 5.9f;
double weight = 70.5;
char initial = 'A';
bool isStudent = true;
std::cout << "Age: " << age << std::endl;
std::cout << "Height: " << height << std::endl;
std::cout << "Weight: " << weight << std::endl;
std::cout << "Initial: " << initial << std::endl;
std::cout << "Is Student: " << isStudent << std::endl;
return 0;
}
Control Flow
If-Else Statement
#include <iostream>
int main() {
int number = 10;
if (number > 0) {
std::cout << "The number is positive." << std::endl;
} else if (number < 0) {
std::cout << "The number is negative." << std::endl;
} else {
std::cout << "The number is zero." << std::endl;
}
return 0;
}
Switch Statement
#include <iostream>
int main() {
int day = 3;
switch (day) {
case 1:
std::cout << "Monday" << std::endl;
break;
case 2:
std::cout << "Tuesday" << std::endl;
break;
case 3:
std::cout << "Wednesday" << std::endl;
break;
default:
std::cout << "Invalid day" << std::endl;
}
return 0;
}
Functions
Function Declaration and Definition
#include <iostream>
void greet() {
std::cout << "Hello, welcome to C++ programming!" << std::endl;
}
int main() {
greet();
return 0;
}
Function with Parameters
#include <iostream>
int add(int a, int b) {
return a + b;
}
int main() {
int sum = add(5, 7);
std::cout << "Sum: " << sum << std::endl;
return 0;
}
Classes and Objects
Defining a Class
#include <iostream>
class Person {
public:
std::string name;
int age;
void introduce() {
std::cout << "Hi, my name is " << name << " and I am " << age << " years old." << std::endl;
}
};
int main() {
Person person1;
person1.name = "Alice";
person1.age = 30;
person1.introduce();
return 0;
}
Inheritance and Polymorphism
Inheritance Example
#include <iostream>
class Animal {
public:
void speak() {
std::cout << "Animal makes a sound." << std::endl;
}
};
class Dog : public Animal {
public:
void speak() {
std::cout << "Dog barks." << std::endl;
}
};
int main() {
Dog myDog;
myDog.speak(); // Calls the Dog's speak method
return 0;
}
Polymorphism Example
#include <iostream>
class Base {
public:
virtual void show() {
std::cout << "Base class" << std::endl;
}
};
class Derived : public Base {
public:
void show() override {
std::cout << "Derived class" << std::endl;
}
};
int main() {
Base* ptr;
Derived derivedObj;
ptr = &derivedObj;
ptr->show(); // Calls Derived's show method
return 0;
}
Templates
Function Templates
#include <iostream>
template <typename T>
T max(T a, T b) {
return (a > b) ? a : b;
}
int main() {
std::cout << "Max of 3 and 7 is " << max(3, 7) << std::endl;
std::cout << "Max of 3.5 and 2.1 is " << max(3.5, 2.1) << std::endl;
return 0;
}
Class Templates
#include <iostream>
template <class T>
class MyArray {
private:
T* arr;
int size;
public:
MyArray(int s) : size(s) {
arr = new T[size];
}
void setValue(int index, T value) {
if (index < size) {
arr[index] = value;
}
}
T getValue(int index) {
if (index < size) {
return arr[index];
}
return T();
}
~MyArray() {
delete[] arr;
}
};
int main() {
MyArray<int> intArray(5);
intArray.setValue(0, 10);
std::cout << "Value at index 0: " << intArray.getValue(0) << std::endl;
MyArray<std::string> strArray(3);
strArray.setValue(0, "Hello");
std::cout << "Value at index 0: " << strArray.getValue(0) << std::endl;
return 0;
}
File I/O
Reading from a File
#include <iostream>
#include <fstream>
#include <string>
int main() {
std::ifstream infile("example.txt");
std::string line;
if (!infile) {
std::cerr << "Error opening file." << std::endl;
return 1;
}
while (std::getline(infile, line)) {
std::cout << line << std::endl;
}
infile.close();
return 0;
}
Writing to a File
#include <iostream>
#include <fstream>
int main() {
std::ofstream outfile("output.txt");
if (!outfile) {
std::cerr << "Error opening file." << std::endl;
return 1;
}
outfile << "This is a test file." << std::endl;
outfile.close();
return 0;
}
Standard Template Library (STL)
Using vector
#include <iostream>
#include <vector>
int main() {
std::vector<int> numbers = {1, 2, 3, 4, 5};
for (int num : numbers) {
std::cout << num << " ";
}
std::cout << std::endl;
return 0;
}
Using map
#include <iostream>
#include <map>
int main() {
std::map<std::string, int> ageMap;
ageMap["Alice"] = 30;
ageMap["Bob"] = 25;
for (const auto& pair : ageMap) {
std::cout << pair.first << " is " << pair.second << " years old." << std::endl;
}
return 0;
}
Summary
This tutorial covers the basic concepts and syntax of C++ programming. C++ is a versatile language that supports multiple programming paradigms and is widely used in various domains. For further learning, refer to The C++ Programming Language by Bjarne Stroustrup.