CPP (C++) Language

"Hello, my name is Sujit Tomar. I first learned C++ in 2021, and I'm still learning it today because I believe that continuous practice and staying updated with new knowledge are essential for growth."

CPP Boilerplate Code

#include<iostream>
#include<string>usingnamespacestd;intmain(){
return0;
}

Data Type

Summary of C++ Data Types

Data Type	Description	Size (Typical)	Example
int	Integer value (whole numbers)	4 bytes	int a = 10;
short	Smaller integer	2 bytes	short b = 5;
long	Larger integer	4 or 8 bytes	long c = 100000;
long long	Very large integer	8 bytes	long long d = 100000000000LL;
unsigned	Non-negative integer (used with any integer)	Depends on type	unsigned int e = 25;
float	Floating-point number (decimal)	4 bytes	float f = 3.14f;
double	Double-precision floating-point number	8 bytes	double g = 3.14159;
long double	Extended precision floating-point number	10 or 12 bytes	long double h = 2.718281828459;
char	Single character	1 byte	char i = 'A';
unsigned char	Non-negative character	1 byte	unsigned char j = 'B';
signed char	Signed character	1 byte	signed char k = 'C';
bool	Boolean value (true or false)	1 byte	bool l = true;
std::string	Sequence of characters (C++ string class)	Depends on size	std::string m = "Hello";
void	No value or unknown type	-	void print() {}
Pointer	Holds memory address of a variable	Depends on system	int* ptr = #

Key Differences Between long and long long

Feature	long	long double
Size	Typically 4 bytes (32-bit) or 8 bytes (64-bit) depending on the system.	Always at least 8 bytes (64-bit)
Range	Depends on the system (on 32-bit systems: -2^31 to 2^31-1, on 64-bit systems: -2^63 to 2^63-1).	Always from -2^63 to 2^63-1 for signed, 0 to 2^64-1 for unsigned.
Purpose	Used for larger integers than int, but may not be large enough on some systems.	Used for integers requiring guaranteed 64-bit size.
Guarantee	Not guaranteed to be 64-bit on all platforms.	Always guaranteed to be at least 64-bit.
When to use?	Use when you need a larger range than int, but not as large as long long.	Use when you need guaranteed 64-bit precision.

Example long and long long

#include<iostream>usingnamespacestd;intmain() {
long num1 = 2147483647; // maximum value for signed 32-bit long (on 32-bit systems)longlong num2 = 9223372036854775807; // maximum value for signed 64-bit long long
cout << "Value of num1 (long): " << num1 << endl;
cout << "Value of num2 (long long): " << num2 << endl;
return0;
}

Key Differences Between double and long double

Feature	double	long double
Size	Typically 8 bytes (64 bits)	Typically 8 bytes (MSVC) or 16 bytes (GCC)
Precision	Around 15-16 decimal digits	Around 18-19 decimal digits or more
Range	~ ±1.7 × 10³⁰	Larger than double, depending on the system
Use Case	General-purpose floating-point values	Higher precision required (e.g., scientific calculations)
Memory	Less memory usage compared to long double	Uses more memory (if 16 bytes)

double Example

#include<iostream>usingnamespacestd;intmain() {
double num1 = 3.141592653589793;
cout << "Value of num1: " << num1 << endl;
return0;
}

long double Example

#include<iostream>usingnamespacestd;intmain() {
longdouble num2 = 3.14159265358979323846264338327950288419716939937510L;
cout << "Value of num2: " << num2 << endl;
return0;
}

Operator in CPP

Arithmetic Operators :- " +, -, *, /, % "

Assignment Operators :- " +=, -=, *=, /=, %= "

Relational Operators :- " > , >=, <, <= "

Logical Operators :- " >> && and || "

**Bitwise Operators :- "(AND) &, (OR) |, (XOR) ^, (NOT) ~, (Left shift) <<, (Right shift) >>"

Increment Operators :- " Prefix: ++x, Postfix: x++ "

Decrement Operators :- " Prefix: --x, Postfix: x--"

Conditionals Statement

"In C++, a conditional statement is a way to make decisions in a program. It allows the program to execute different blocks of code based on whether a certain condition is true or false. These conditions are usually based on comparing values., such as checking if a number is greater than another number or if a certain condition is met.

In simple terms, conditional statements help your program decide what to do next based on certain situations."

if Statement

syntax

if (condition) {
// code to be executed if condition is true
}

example

#include<iostream>usingnamespacestd;intmain() {
int x = 10;
if (x > 5) {
cout << "x is greater than 5" << endl;
}
return0;
}

if else Statement

syntax

if (condition) {
// Block of code that executes if condition is true
} else {
// Block of code that executes if condition is false
}

example

#include<iostream>usingnamespacestd;intmain() {
int x = 10;
if (x > 5) {
cout << "x is greater than 5" << endl;
} else {
cout << "x is 5 or less" << endl;
}
return0;
}

else if Statement

syntax

if (condition1) {
// Code block executed if condition1 is true
} elseif (condition2) {
// Code block executed if condition2 is true
} elseif (condition3) {
// Code block executed if condition3 is true
} else {
// Code block executed if none of the conditions are true
}

example

#include<iostream>usingnamespacestd;intmain() {
int x = 7;
if (x > 10) {
cout << "x is greater than 10" << endl;
} elseif (x > 5) {
cout << "x is greater than 5 but less than or equal to 10" << endl;
} elseif (x > 0) {
cout << "x is greater than 0 but less than or equal to 5" << endl;
} else {
cout << "x is less than or equal to 0" << endl;
}
return0;
}

Switch Statement

syntax

switch (expression) {
case value1:
// Code block executed if expression == value1break;
case value2:
// Code block executed if expression == value2break;
case value3:
// Code block executed if expression == value3break;
// Optionally, more cases...default:
// Code block executed if no case matches the expressionbreak;
}

example

#include<iostream>usingnamespacestd;intmain() {
int day = 3;
switch (day) {
case1:
cout << "Monday" << endl;
break;
case2:
cout << "Tuesday" << endl;
break;
case3:
cout << "Wednesday" << endl;
break;
case4:
cout << "Thursday" << endl;
break;
case5:
cout << "Friday" << endl;
break;
case6:
cout << "Saturday" << endl;
break;
case7:
cout << "Sunday" << endl;
break;
default:
cout << "Invalid day" << endl;
break;
}
return0;
}

Tarnary Operator

syntax

 condition ? value_if_true : value_if_false;

example

#include<iostream>usingnamespacestd;intmain() {
int age = 20;
string result = (age >= 18) ? "Adult" : "Minor";
cout << "You are an " << result << "." << endl;
return0;
}

Loop in cpp

In C++, there are several types of loops that allow you to repeat a block of code multiple times based on certain conditions. The main types of loops are:

for loop

The for loop is typically used when you know beforehand how many times you want to repeat a block of code.

syntax

for (initialization; condition; increment/decrement) {
// Code to be executed
}

example

#include<iostream>usingnamespacestd;intmain() {
for (int i = 1; i <= 5; i++) {
cout << "i = " << i << endl;
}
return0;
}

output

i = 1
i = 2
i = 3
i = 4
i = 5

while loop

The while loop is used when you want to repeat a block of code an unknown number of times, as long as a condition is true. It checks the condition before executing the loop body.

syntax

while (condition) {
// Code to be executed
}

example

#include<iostream>usingnamespacestd;intmain() {
int i = 1;
while (i <= 5) {
cout << "i = " << i << endl;
i++;
}
return0;
}

output

i = 1
i = 2
i = 3
i = 4
i = 5

do-while loop

The do-while loop is similar to the while loop, but it checks the condition after executing the loop body. This guarantees that the loop body is executed at least once.

syntax

do {
// Code to be executed
} while (condition);

example

#include<iostream>usingnamespacestd;intmain() {
int i = 1;
do {
cout << "i = " << i << endl;
i++;
} while (i <= 5);
return0;
}

output

i = 1
i = 2
i = 3
i = 4
i = 5

Range Base for loop with std::vector

example

#include<iostream>
#include<vector>usingnamespacestd;intmain() {
vector<int> vec = {10, 20, 30, 40, 50};
for (int val : vec) {
cout << "Value: " << val << endl;
}
return0;
}

output

Value: 10
Value: 20
Value: 30
Value: 40
Value: 50

Function in cpp

In C++, a function is a block of code that performs a specific task. Functions help in breaking down the code into smaller, reusable pieces, improving modularity and readability.

syntax

return_type function_name(parameter_list)
{
// function body// perform operationsreturn value; // optional, depending on the return_type
}

example

#include<iostream>usingnamespacestd;// Function to add two integers and return the resultintadd(int a, int b) {
return a + b; // return the sum of a and b
}
intmain() {
int result = add(5, 3); // calling the function with arguments 5 and 3
cout << "The sum is: " << result << endl;
return0;
}

output

 The sum is: 8

Type of Function

In C++, functions can be categorized into different types based on their return types, parameters, and other features. The major types of functions in C++ are:

Standard Functions (or Built-in Functions)

Example

#include<iostream>
#include<cmath>// for math functionsintmain() {
double x = 16.0;
double result = sqrt(x); // sqrt is a standard function to compute square root
std::cout << "Square root of " << x << " is: " << result << std::endl;
return0;
}

output

 Square root of 16 is: 4

User-defined Functions

Function with No Arguments

synax

voidfunctionName() {
// Code
}

example

#include<iostream>voidgreet() {
std::cout << "Hello, welcome to C++!" << std::endl;
}
intmain() {
greet(); // Calling the functionreturn0;
}

output

Hello, welcome to C++!

Function with Arguments

syntax

return_type functionName(parameter1, parameter2, ...) {
// Code
}

example

#include<iostream>intadd(int a, int b) {
return a + b;
}
intmain() {
int sum = add(5, 3); // Calling the function with arguments
std::cout << "Sum: " << sum << std::endl;
return0;
}

output

Sum: 8

Function with Return Value

syntax

return_type functionName(parameters) {
// Codereturn value;
}

example

#include<iostream>floatdivide(float a, float b) {
return a / b;
}
intmain() {
float result = divide(10.0, 2.0); // Calling the function with arguments
std::cout << "Division Result: " << result << std::endl;
return0;
}

output

Division Result: 5

Functions with default arguments

syntax

return_type functionName(parameter1, parameter2 = default_value) {
// Code
}

example

#include<iostream>intmultiply(int a, int b = 2) {
return a * b;
}
intmain() {
std::cout << multiply(4, 5) << std::endl; // Uses both arguments
std::cout << multiply(4) << std::endl; // Uses default value for breturn0;
}

output

Inline Functions

An inline function is a function where the compiler replaces the function call with the actual code of the function, thereby potentially improving performance by avoiding the overhead of function calls. Inline functions are typically small, and the keyword inline is used to define them.

syntax

inline return_type functionName(parameters) {
// Code
}

Example

#include<iostream>inlineintsquare(int x) {
return x * x;
}
intmain() {
std::cout << "Square of 5: " << square(5) << std::endl;
return0;
}

output

Square of 5: 25

Recursive Functions

A recursive function is a function that calls itself. Recursion is often used for problems that can be broken down into smaller subproblems, such as calculating factorials or Fibonacci numbers.

syntax

return_type functionName(parameters) {
if (base_condition) {
return base_value;
}
returnfunctionName(new_parameters); // Recursive call
}

example

#include<iostream>intfactorial(int n) {
if (n == 0) // Base conditionreturn1;
elsereturn n * factorial(n - 1); // Recursive call
}
intmain() {
int num = 5;
std::cout << "Factorial of " << num << " is: " << factorial(num) << std::endl;
return0;
}

output

Factorial of 5 is: 120

Friend Functions

A friend function is a function that is not a member of a class but has access to the class's private and protected members. This is useful when you need to perform operations that involve more than one class but need access to the private data.

syntax

classMyClass {
private:int data;
public:MyClass(int val) : data(val) {}
friendvoiddisplayData(MyClass obj); // Friend function declaration
};
voiddisplayData(MyClass obj) {
std::cout << "Data: " << obj.data << std::endl; // Accessing private member
}
intmain() {
MyClass obj(10);
displayData(obj); // Calling the friend functionreturn0;
}

output

Data: 10

Virtual Functions

A virtual function is a function that is declared in the base class and overridden in the derived class. It allows you to use polymorphism, where the function that gets called depends on the type of the object, not the reference.

syntax

classBase {
public:virtualvoidshow() {
std::cout << "Base class show function" << std::endl;
}
};
classDerived : publicBase {
public:voidshow() override {
std::cout << "Derived class show function" << std::endl;
}
};
intmain() {
Base* ptr;
Derived obj;
ptr = &obj;
ptr->show(); // Will call Derived class's show()return0;
}

output

Derived classshow function

Name		Name	Last commit message	Last commit date
Latest commit History 88 Commits
.vscode		.vscode
01 _Introduction		01 _Introduction
02_varconst		02_varconst
03_primitives		03_primitives
04_operators		04_operators
05_conditionals		05_conditionals
06_Loop		06_Loop
07_function		07_function
08_array		08_array
09_oop		09_oop
test		test
README.md		README.md

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CPP (C++) Language

CPP Boilerplate Code

Data Type

Key Differences Between long and long long

Example long and long long

Key Differences Between double and long double

double Example

long double Example

Operator in CPP

Conditionals Statement

if Statement

syntax

example

if else Statement

syntax

example

else if Statement

syntax

example

Switch Statement

syntax

example

Tarnary Operator

syntax

example

Loop in cpp

for loop

syntax

example

output

while loop

syntax

example

output

do-while loop

syntax

example

output

Range Base for loop with std::vector

example

output

Function in cpp

syntax

example

output

Type of Function

Standard Functions (or Built-in Functions)

Example

output

User-defined Functions

Function with No Arguments

synax

example

output

Function with Arguments

syntax

example

output

Function with Return Value

syntax

example

output

Functions with default arguments

syntax

example

output

Inline Functions

syntax

Example

output

Recursive Functions

syntax

example

output

Friend Functions

syntax

update soon for more content " Thank You "
Sujit Tomar