# Types of Functions

There are three types of functions. They are
• Function with no arguments and no return values.
• Functions with arguments and no return values.
• Functions with arguments and return values.
Functions with no arguments and no return values:
• This is the simplest function.
• This does not receive any arguments from the calling function and does not return to the calling functions.
Example

void main()

{

int a,b;

--------

--------

message();

______

______

}

void message()

{

_______

_______

}

 #include void main() { sum(); } sum() { int i,j,k; cin>>i>>j; x= i + j; cout<< "sum="<

# Function with arguments and no return values

This function receives arguments from the calling function and does not return any value to the calling function.
Example

void main()

{

int a,b;

-------

-------

message (a,b);

---------

---------

}

void message(int x, int y)

{

-----------

-----------

}

Program
 #include void main() { int I,j; cin >> I >>j; sum(i,j); } void sum(int x, int y) { int z; z = x + y; cout <<"sum="<

# Function with arguments and return values

• This function receives arguments from the calling function and returns the computed value back to the calling function.
Example

void main()

{

int a,b,c;

----------

----------

c=message(a,b);

}

int message(int x,int y)

{

int value;

----------

----------

value = x +y;

return(value);

}

Program

 #include void main() { int i,j,value; cin >> i >> j; value=sum(i,j); cout<<"sum="<

# Call by Reference

• A function is called by call by reference means the value of the actual arguments are passed to the function through the reference variables

• Using this type of calling we can access the actual parameters through its alias names.

• So any change made to the formal arguments is seen in the actual arguments.

• That is when function is working with its own arguments, it is actually working on the original data

• The general form is

 Datatype function_name (datatype1&, datatype2&.......);
Where
Datatype - valid data type such as int, float etc.
function_name - name of the defined function.
& - reference operator