Purpose: Utilize Inheritance

General requirements:

$-$ All data members must be declared as $$private$$

$-$ No global variable is allowed to be declared and used $($constants are ok$)$

$-$ No multiple return statements in one function

$-$ Show how you have tested these functions

$-$ cin and cout are not allowed in these classes and methods. They can only be in main$()$ or testing functions

$-$ These classes should not provide the default constructor.

$-$ You can put all class definitions in one file or multiple files. It's your choice.

Part $1$:

Define a class named $$Variable$$ that manages a variable name $($string$).$ It should not provide the default constructor.

The class must at least provide the following methods:

$-$ toString$()$ method that can return a string in the following format:

VAR$()$ such as VAR$($isSuccessful$)$

$-$ contains$()$ that accepts a search string and it will return true if its variable

name contains that string $($case$-$insensitive$)$ and false otherwise.

Show how this class being used to create objects and call all its methods and show

how they work.

Part $2$:

Write a new class named $$VariableString$$ that must inherit from the

"Variable" class. This class manages a variable name $($string$)$ and a

value $($string$).$ Please note that this class must make use of inheritance.

The class must at least provide the following methods:

$-$ toString$()$ method that can return a string in the following format:

VAR$()$ VALUE$()$

such as VAR$($greeting$)$ VALUE$("$Hello$,$ World!"$)$

$-$ override the "contains" method so that it not only searches through the name but also the value of the string.

Part $3$

Write a new class named $$VariableInt$$ that must inherit from the

"Variable" class. This class manages a variable name $($string$)$ and a

value $($integer$).$ Please note that this class must make use of inheritance.

The class must at least provide the following methods:

$-$ toString$()$ method that can return a string in the following format:

VAR$()$ VALUE$()$

such as VAR$($count$)$ VALUE$(100)$

Part $4$

Write a function named $$findVariables$$ that accepts a vector of Variable

object pointers and a search string. It will return the list of Variable

object pointers that contains that search string.

Please note that the list can contain pointers to Variable, VariableString or VariableInt objects

or any of its derived class objects.

Part $5$

The main$()$ function:

$1.$ Build a list of pointers pointing to mixed objects of Variable, VariableString and VariableInt objects

and show your function returns the mix of three different types.

$2.$ Show how you test all methods defined in the above classes

for c$++$ class please