Creating own functions (subroutings)
To make it easier to understand and correct the text of programs, you can allocate its fragments into separate routines.
The same is done with repeated fragments containing a tangible number of lines of program text.
Such fragments are written below the main() function after its last curly brace.
They are given a name, equipped with incoming arguments and a return value.
Example.
Output text to the message window, depending on the code passed to the subroutine.
int main()
{
cout << "String from function with arg 1 = " << get_string(1) << ", the same, but with arg 2 = " << get_string(2);
}
// function declaration, takes the argument arg - an integer.
// returns a string value.
string get_string(int arg)
{
string sresult;
if (arg == 1) // if arg eq 1
{
sresult = "string 1"; // then assign this value to the sresult variable.
}
else if (arg == 2) // if arg is eq 2
{
sresult = "string 2";
}
else // if it not 1 and no 2, than with all other values
{
sresult = "string N"; // assign to variable sresult this value.
}
return sresult; // return as result of the function content of the sresult variable.
}
Several variables (arguments) can be passed to the subroutine at once. Then they are written separated by commas.
Example.
Declare a function that takes two integers and one floating-point number as arguments, and returns a floating-point value.
double my_func(int a, int b, double c)
{
return 10;
}
Due to the fact that the C++ text has a high execution speed, you can create any number of your own functions.