Passing variable from function A to main and back to another - c++

Question

I have the following example
int main() {
...
}
void parameterList() {
...
}
void myMethodA() {
...
}
void myMethodB() {
...
}
void myMethodC() {
...
}
I have read several StackOverflow posts on this subject and understand to pass a variable from myMethodA() to myMethodB(), I will need to call myMethodB() in myMethodA() with the variables. To illustrate
void parameterList() {
...
int someInteger = 45;
string someName = "John";
int otherInteger = 20;
myMethodB(someName, someIntegers);
myMethodC(otherInteger);
}
void myMethodB(string &someName, int &someInteger) {
...
string another_someName = someName;
int another_someInteger = someInteger;
...
}
void myMethodC(int &otherInteger) {
...
int another_someInteger_two = otherInteger;
...
}
parameterList() is a function where it contains multiple variables for multiple myMethod() functions. On initial program run, parameterList() will have to run first in main to get all the necessary variable. Ideally, the main function will obtain all these variables from parameterList() and pass it to myMethod() in main function. To illustrate
Step 1
main function will run parameterList()
Step 2
parameterList() process and have multiple variables meant for multiple myMethod()
Step 3
main function should have a variable that can "store" these variables in order to pass it to all the myMethod() for further processing
The main function will not run myMethodB() until it is told to do so and when the variables from myMethodA() is inside the main.
Any clarification on this is greatly appreciated. Thanks for taking your time!

Answer 1

You could also use a class to wrap data and also manage the lifetime of the objects.
class Context {
int someInteger;
string someName;
Context(int a, const string& b) :
someInteger(a),
someName(b)
{}
void myMethodA() {
/* do something with someInteger and someName */
}
void myMethodB() {
/* do something with the results from myMethodA */
}
};
int main() {
Context ctx{45, "John"};
ctx.myMethodA();
ctx.myMethodB();
}

Answer 2

Passing variable from function A to main and back to another
To pass a value out of a function, you can return it.
To pass a value into a function, you can use a parameter. Example:
int myMethodA() {
int someInteger = 45;
// ...
return someInteger;
}
int main()
{
int someInteger = myMethodA();
myMethodB(someInteger);
}
I don't think this will work if myMethodA() will need to return more than 1 variable
That's not a problem. While only one object can be returned, that object can be of a class type, and classes can contain more than one sub object. Example:
struct example {
int someInteger;
string someName;
};
example myMethodA();
void myMethodB(const example&);
If it makes sense for the structure of the program, the functions could potentially be made member functions of the class such as demonstrated in KamilCuk's answer.
Can the struct have array?
Yes. Class members can be arrays.
Is 'example myMethodA()', is that in the main function?
That is a declaration of a function that returns instance of example.
How should I return these variables in myMethodA() inside myMethodA() return?
Same way as you return other objects. With the return statement.