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C++ Introduction
course content

Course Content

C++ Introduction

C++ Introduction

1. Getting Started
Why to Learn C++What is C++Entry Point of a ProgramStandard Library and FilesPreprocessor DirectivesThe First Program
2. Variables and Data Types
Introduction to VariablesData TypesNumerical Data TypesIntroduction to StringIntroduction to ArraysKeywords sizeof(), auto and typedefWorking with the Array
3. Introduction to Operators
Simple OperatorsA Little MathLogical OperatorsCompound Assignment OperatorPracticing Math Basics
4. Introduction to Program Flow
If...else StatementTernary OperatorSwitch StatementWhile LoopDo...while LoopFor LoopFibonacci Number with Loops
5. Introduction to Functions
What are Functions?Type of FunctionsReturn Statement in FunctionsFunctions With Arguments Simple Function

bookKeywords sizeof(), auto and typedef

The size of a variable is the amount of memory reserved by the compiler. The compiler reserves a specific number of bytes from your computer's memory, based on the data type you are using. You can use the sizeof() function to find out the size of a variable or data type in bytes.

cpp

main

copy

              
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#include <iostream>

int main()
{
	int myVar1;
	char myVar2;

	std::cout << "Size of int: " << sizeof(myVar1) << std::endl;
	std::cout << "Size of char: " << sizeof(myVar2) << std::endl;
}

C++ allows you to select a type with a precise bit size, such as int8_t, uint8_t, int16_t,uint16_t, etc. To use these data types, you will need to include the <cstdint> header file.

Additionally, we can force the compiler to determine the variable type on its own using the auto keyword.

cpp

main

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#include <iostream>

int main()
{
	auto myVar = 64.565;

	std::cout << "Value of myVar : " << myVar << std::endl;

	// double type takes 8 bytes
	std::cout << "Size of myVar : " << sizeof(myVar) << std::endl;
}

C++ also allows you to rename existing data types for yourself. This is what typedef is used for.

cpp

main

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#include <iostream>

int main()
{
	//change name of double type to MY_NEW_TYPE
	typedef double MY_NEW_TYPE;

	MY_NEW_TYPE myVar = 64.565;

	std::cout << "Value of myVar: " << myVar << std::endl;

	// double type takes 8 bytes
	std::cout << "Size of myVar : " << sizeof(myVar) << std::endl;
}

When compiled, the typedef line tells the compiler that MY_NEW_TYPE is just a double type.

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Section 2. Chapter 6
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