C++ Cheatsheet 📜

A collection of C++ snippets that explain how the language works.

More fun stuff ⚡

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Made possible by @TheCherno 🚀

Cherno makes programming tutorials focused on C++. The concepts explained in this repo reference his explanations from different videos.

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First video

Contribution 🤝

Feel free to contribute your code or point out any issues. We're all human, mistakes in this code are inevitable, but unlikely.

Built-in data types 🛠️

https://www.tutorialspoint.com/cplusplus/cpp_data_types.htm

Data type	Size	Range (approx.)
bool	1 byte	0 and 1
char	1 byte	-127 to 127
unsigned char	1 byte	0 to 255
short (int)	2 bytes	-32768 to 32767
unsigned short	2 bytes	0 to 65535
int	4 bytes	-2147483648 to 2147483647
unsigned int	4 bytes	0 to 4294967295
long (int)	8 bytes	-9223372036854775808 to 9223372036854775807
unsigned long	8 bytes	0 to 18446744073709551615
long long	8 bytes	-(2^63) to (2^63)-1
unsigned long long	8 bytes	0 to 18446744073709551615
float	4 bytes	Floating point numbers
double	8 bytes	Floating point numbers
long double	12 bytes	Floating point numbers
auto	-	-

auto is a placeholder for a data type that is automatically deduced by the compiler: Cherno's video

Operators 🧮

https://www.tutorialspoint.com/cplusplus/cpp_operators.htm

Operator	Description
sizeof	Returns the size of a variable
&	Returns the address of a variable
*	Pointer to a variable
? :	Conditional operator
.	Member operator
->	Member operator
++	Increments the value of a variable
--	Decrements the value of a variable
+	Adds two operands
-	Subtracts two operands
*	Multiplies two operands
/	Divides two operands
%	Modulus operator
=	Assigns values from right side operands to left side operand
+=	Adds right operand to the left operand and assign the result to left operand
-=	Subtracts right operand from the left operand and assign the result to left operand
*=	Multiplies right operand with the left operand and assign the result to left operand
/=	Divides left operand with the right operand and assign the result to left operand
%=	Takes modulus using two operands and assign the result to left operand
==	Checks if the values of two operands are equal or not. If yes, then the condition becomes true
!=	Checks if the values of two operands are equal or not. If the values are not equal, then the condition becomes true
>	Checks if the value of left operand is greater than the value of right operand. If yes, then the condition becomes true
<	Checks if the value of left operand is less than the value of right operand. If yes, then the condition becomes true
>=	Checks if the value of left operand is greater than or equal to the value of right operand. If yes, then the condition becomes true
<=	Checks if the value of left operand is less than or equal to the value of right operand. If yes, then the condition becomes true
&&	Called Logical AND operator. If both the operands are non-zero, then the condition becomes true
||	Called Logical OR Operator. If any of the two operands is non-zero, then the condition becomes true
!	Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true, then Logical NOT operator will make it false

Access Specifiers 🔒

Specifier	Description
public	Members are accessible from outside the class
private	Members cannot be accessed (or viewed) from outside the class
protected	Members cannot be accessed from outside the class, however, they can be accessed in inherited classes

Other Specifiers 📌

Specifier	In this repo	C++ Reference	Description
const	const.cpp	Link	Makes a variable immutable
static	static.cpp	Link	Makes a variable or function static
extern	static.cpp	Link	Declares a variable that is defined in another translation unit or that is defined externally
inline	NULL	Link	Instructs the compiler to insert a copy of the code of a function at the point where the function is called at compile time
constexpr	NULL	Link	Instructs the compiler to evaluate the value of an expression at compile time
virtual	virtual.cpp	Link	Declares a function that can be overridden in a derived class
override	virtual.cpp	Link	Specifies that a virtual function overrides another virtual function
final	NULL	Link	Specifies that a virtual function cannot be overridden in a derived class or that a class cannot be inherited from
explicit	explicit.cpp	Link	Prevents a type to be converted to another type implicitly
friend	NULL	Link	Grants a function or another class access to private and protected members of a class

inline vs constexpr: Explanation

Stack vs Heap 📚

https://www.youtube.com/watch?v=wJ1L2nSIV1s&list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb&index=54

	Stack	Heap
Initialization	int a;	int* a = new int;
Memory Allocation	int a[5];	int* a = new int[5];
Access	a = 2;	*a = 2;
Deletion	Automatically when out of scope	delete a;
Size	Smaller	Larger
Stored	Together in memory	Fragmented
Allocating	Costs around 1 CPU instruction	Costs a lot more

Casting 🎭

https://www.tutorialspoint.com/cplusplus/cpp_casting_operators.htm

Operator	Description
static_cast	Checks if the type of the expression is compatible with the target type and converts it if possible.
reinterpret_cast	Converts any pointer type to any other pointer type. The operation result is a simple binary copy of the value from one pointer to the other. (type punning)
const_cast	Modifies the const, volatile, and __unaligned attributes of the type. (usually used to remove const)
dynamic_cast	Returns a null pointer of the target type if the conversion is not possible.