Learn Return Statement in Functions | Introduction to Functions

The return statement terminates the execution of a function and returns a value of a predefined type.

function.h


              12345
            
int func() // int - predefined
{
    int variable = 10; 
	return variable; // variable = 10
}

If the type is specified incorrectly, the function will behave unpredictably.

main.cpp


              12345678910111213
            
#include <iostream>

unsigned short func() 
{
	return -10;
}

// The unsigned short data type has no negative values.

int main()
{
	std::cout << func() << std::endl;
}

That is, before creating a function, the type of data that it returns must be specified. Also, in C++, there are special void functions. Functions of this data type are allowed to return nothing:

first_example.cpp

second_example.cpp


              123456789101112
            
#include <iostream>

void voidFunction()
{
	std::cout << "It's void function!" << std::endl;
	// Function without return
}

int main()
{
	voidFunction();
}

There can be multiple returns inside functions, and each one will only fire under certain conditions.

main.cpp


              1234567891011121314151617
            
#include <iostream>

int func()
{
	int a = 50;
	int b = 6;

	if (a > b) // If `a > b`, func will `return a`
		return a;
	else       // Otherwise func will `return b`
		return b;
}

int main()
{
	std::cout << func() << std::endl; // Func calling
}

If there are two returns, the second return function will be ignored:

main.cpp


              123456789101112131415
            
#include <iostream>

int func()
{
	int a = 50; // Declare variable a
	int b = 6;  // Declare variable b

	return a; // Function stops here, b is never returned
	return b; // Unreachable
}

int main()
{
	std::cout << func() << std::endl; // Call func and print result
}

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Thanks for your feedback!

Section 5. Chapter 3

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The return statement terminates the execution of a function and returns a value of a predefined type.

function.h


              12345
            
int func() // int - predefined
{
    int variable = 10; 
	return variable; // variable = 10
}

If the type is specified incorrectly, the function will behave unpredictably.

main.cpp


              12345678910111213
            
#include <iostream>

unsigned short func() 
{
	return -10;
}

// The unsigned short data type has no negative values.

int main()
{
	std::cout << func() << std::endl;
}

first_example.cpp

second_example.cpp


              123456789101112
            
#include <iostream>

void voidFunction()
{
	std::cout << "It's void function!" << std::endl;
	// Function without return
}

int main()
{
	voidFunction();
}

There can be multiple returns inside functions, and each one will only fire under certain conditions.

main.cpp


              1234567891011121314151617
            
#include <iostream>

int func()
{
	int a = 50;
	int b = 6;

	if (a > b) // If `a > b`, func will `return a`
		return a;
	else       // Otherwise func will `return b`
		return b;
}

int main()
{
	std::cout << func() << std::endl; // Func calling
}

If there are two returns, the second return function will be ignored:

main.cpp


              123456789101112131415
            
#include <iostream>

int func()
{
	int a = 50; // Declare variable a
	int b = 6;  // Declare variable b

	return a; // Function stops here, b is never returned
	return b; // Unreachable
}

int main()
{
	std::cout << func() << std::endl; // Call func and print result
}

Everything was clear?

Thanks for your feedback!

Section 5. Chapter 3