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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

bookType of Functions

When creating a function, the data type it returns always specified.

In the example of the main function, we see that it has an integer data type, which means that after it finishes its work, it will return an integer value, in our case, the number 0.

Note

Since the main function is reserved in C++, it will always return integer.

But our functions can return any value:

To call a function, you need to write its name with brackets:

cpp

main

copy

              
1234567891011

            
#include <iostream>

double notMainFunc()
{
	return 3.14;
}

int main()
{
	std::cout << notMainFunc();
}

We have created a function that returns a value of 3.14 as a double data type, and we have called this function to display its output on the screen.

Functions can also be string type:

cpp

main

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123456789101112

            
#include <iostream>
#include <string>

std::string notMainFunc() //string function
{
	return "codefinity";
}

int main()
{
	std::cout << notMainFunc(); //calling string function
}

The typedef is also applicable:

cpp

main

copy

              
12345678910111213

            
#include <iostream>

typedef int MY_NEW_TYPE;

MY_NEW_TYPE TYPEfunc() //MY_NEW_TYPE function
{
	return 777;
}

int main()
{
	std::cout << "New type func returned " << TYPEfunc() << std::endl;
}

If you can't exactly specify the return type, the auto operator will force the compiler to do it for you:

cpp

main

copy

              
1234567891011121314151617

            
#include <iostream>

auto autoFunc1() // first auto-type function
{
	return 777;
}

auto autoFunc2() // second auto-type function
{
	return 123.412;
}

int main()
{
	std::cout << "First auto-type function returned " << autoFunc1() << std::endl;
	std::cout << "Second auto-type function returned " << autoFunc2() << std::endl;
}

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Section 5. Chapter 2
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