Objectives:

Solve problem, design solution and implement using C$++$ classes and objects

Learn how to manipulate a list of C$++$ objects using vector class

Use C$++$ stream to read in data and format output

Description:

Write a command$-$driven program named "ManageVariableObjects" that will accept the following commands:

$=$

list

exit

$=$

save away the variable and its value in the list $($array$).$

If the variable has been assigned before, it simply updates with the new value

Note: the variable$-$value can now be another variable name.

If the value is another variable name, it will look up and save its value into the new variable.

display the current value of the variable in the following format $()$ such as count$(10)$

or "undefined"

"list" command will display all the variables and its count

"exit" command will exit the program

Requirements:

$1.$ The program must produce the same expected output as provided.

$2.$ There should be no global variables. Please use only local variables and parameters instead

$3.$ Scanf and printf are not allowed $($Please use C$++$ cin and cout and C$++$ formatting$)$

$4.$ It should display "Undefined" when the variable is not assigned yet

$5.$ You must define at least two more C$++$ classes:

$-$ Variable class that manages variable information such as name and value

$-$ VariableListManager class that manages a list of Variable object pointers $($not objects$)$ using the vector class.

It means that the Variable object is outside the vector object and you must create the objects using "new" operator.

$6.$ Simple error check for variable names: cannot start with a digit.

$7.$ There must be at least $5$ functions including main$()$

$8.$ Please do not use arrays. You must use the C$++$ vector class to manage the list of object pointers.

$9.$ The vector must be a private data member in the "VariableListManager" class. No vector class and object

can be referenced or used outside the VariableListManager class.

$10.$ Please minimize redundant code. Please write functions if you need to perform the same tasks multiple times.

$11.$ There should be at most one return statement in each function.

$12.$ Please do not iterate through the list in the vector more than once for each task and please do not iterate to the end of the list unnecessarily.

$13.$ You should not define the maximum size limit and not to keep track of its actual number of variables separately because the vector object has its size.

$14.$ You can assume that the user enters the variable assignment correctly $($e$.$g$.$ correct $\text{'}=\text{'}$ operator and integer value separated by blanks$)$

$15.$ All data members must be declared private in the class.

$16.$ The "Variable" class must not provide the default constructor.

Sample output of a program run:

Please note that the output of the project #$1$ will continue to work and display the same result.

Here is the new additional run and output:

C:$\backslash >$ ManageVariableObjects

Please enter variable assignment, variable name only or list or exit:

$1$count

Undefined

count

Undefined

count $=10$

count$(10)$

count

count$(10)$

list

count$(10)$

Number of variables: $1$

total $=15$

total$(15)$

list

count$(10)$

total$(15)$

Number of variables: $2$

duplicate

Undefined

count $=$ duplicate

Undefined

duplicate $=$ count

duplicate$(10)$

count $=12$

count$(12)$

list

count$(12)$

total$(15)$

duplicate$(10)$

Number of variables: $3$

total $=$ count

total$(12)$

list

count$(12)$

total$(12)$

duplicate$(10)$

Number of variables: $3$

count

count$(12)$

total

total$(12)$

duplicate

duplicate$(10)$

quantity $=25$

quantity$(25)$

list

count$(12)$

total$(12)$

duplicate$(10)$

quantity$(25)$

Number of variables: $4$

count $=$ quantity

count$(25)$

$1$count

Undefined

price

Undefined

price $=$ quantity

price$(25)$

list

count$(25)$

total$(12)$

duplicate$(10)$

quantity$(25)$

price$(25)$

Number of variables: $5$

duplicate $=$ temp

Undefined

temp $=$ duplicate

temp$(10)$

quit

Undefined

$1$count $=10$

Invalid variable name. Cannot start with a digit.

exit

Exiting...