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Oct 10th, 2008

[need help] Initializing Objects in Control Structures

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I'm having trouble initializing Objects while they're inside if else statements. I'm using Visual C++ 2008.

for instance:

C++ Syntax (Toggle Plain Text)
class Account {
  Account();
  Account(int = idnum, double creditLimit = 500.00);
  Account(double initBal, int idnum, double creditLimit = 100.00);
public:
  somefunction();
};
 
if (a > 0 && b > 0) {
  Account customer(a,b);
} else {
  Account customer;
}
 
customer.somefunction();
class Account {
  Account();
  Account(int = idnum, double creditLimit = 500.00);
  Account(double initBal, int idnum, double creditLimit = 100.00);
public:
  somefunction();
};

if (a > 0 && b > 0) {
  Account customer(a,b);
} else {
  Account customer;
}

customer.somefunction();

it would me this error:

Quote ...

error C2065: 'customer' : undeclared identifier
error C2228: left of '.somefunction' must have class/struct/union

i know that this means, i just don't know if there's a better way to do this.

i'm required to take account information and initialize the object depending on the user's input.

i was thinking i'd use if else statements then create the object, but apparently that doesn't work.

mbayabo

Reputation Points: 10

Solved Threads: 0

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since Oct 2008

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Oct 10th, 2008

Re: [need help] Initializing Objects in Control Structures

No need to have this if else , use customer(a,b) , in the constructor check if a>0 , b>0 if no set the default value.

ithelp

Reputation Points: 769

Solved Threads: 128

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since May 2006

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Oct 10th, 2008

Re: [need help] Initializing Objects in Control Structures

You declare local variables in if-else alternatives. Of course, they were discarded outside if-else statement:

C++ Syntax (Toggle Plain Text)
if (a > 0 && b > 0) { // New block started
  Account customer(a,b); // Local variable defined (on the stack)
} else { // Prev. bock is ended. Another block started.
  Account customer; // Local variable defined
} // All customers dead... RIP...
// Alas, no customers here...
if (a > 0 && b > 0) { // New block started
  Account customer(a,b); // Local variable defined (on the stack)
} else { // Prev. bock is ended. Another block started.
  Account customer; // Local variable defined
} // All customers dead... RIP...
// Alas, no customers here...

ArkM

Reputation Points: 1234

Solved Threads: 347

Postaholic

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2,001 posts
since Jul 2008

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Oct 10th, 2008

Re: [need help] Initializing Objects in Control Structures

Hi maybe the following suits your problem:

c++ Syntax (Toggle Plain Text)
#include <iostream>
 
class Account {
public:
	Account() : initBal(0),idnum(0),creditLimit(0.0) {}
	Account(int id): idnum(id) 
	{
		initBal=100;
		creditLimit=500.0;
	}
	Account(int balance,int id): initBal(balance),idnum(id) 
	{
		creditLimit=100.0;
	}
public:
  void somefunction()
  {
		  std::cout<<"Initial balance is: "<<initBal<<std::endl;
		  std::cout<<"id is: "<<idnum<<std::endl;
		  std::cout<<"credit Limit is: "<<creditLimit<<std::endl;
  }
  Account& operator=(const Account& other)
  {
	 if (&other != this) 
	 {
		 initBal = other.initBal;
		 idnum = other.idnum;
		 creditLimit = other.creditLimit;
	 }
	 return *this;
  }
private:
	int initBal;
	int idnum;
	double creditLimit;
};
 
int main()
{	
	Account customer;
	int a,b;
 
	std::cout<<"please enter a value for a: "<<std::endl;
	std::cin>>a;
	std::cout<<"please enter a value for b: "<<std::endl;
	std::cin>>b;
 
	if (a > 0 && b == 0) 
	{
		Account alocalcustomer(a);
		customer = alocalcustomer;
	} 
	else if (a > 0 && b > 0)
	{
		Account anotherlocalcustomer(a,b);
		customer = anotherlocalcustomer;
	}
	customer.somefunction();
	return 0;
}
#include <iostream>

class Account {
public:
	Account() : initBal(0),idnum(0),creditLimit(0.0) {}
	Account(int id): idnum(id) 
	{
		initBal=100;
		creditLimit=500.0;
	}
	Account(int balance,int id): initBal(balance),idnum(id) 
	{
		creditLimit=100.0;
	}
public:
  void somefunction()
  {
		  std::cout<<"Initial balance is: "<<initBal<<std::endl;
		  std::cout<<"id is: "<<idnum<<std::endl;
		  std::cout<<"credit Limit is: "<<creditLimit<<std::endl;
  }
  Account& operator=(const Account& other)
  {
	 if (&other != this) 
	 {
		 initBal = other.initBal;
		 idnum = other.idnum;
		 creditLimit = other.creditLimit;
	 }
	 return *this;
  }
private:
	int initBal;
	int idnum;
	double creditLimit;
};

int main()
{	
	Account customer;
	int a,b;
	
	std::cout<<"please enter a value for a: "<<std::endl;
	std::cin>>a;
	std::cout<<"please enter a value for b: "<<std::endl;
	std::cin>>b;
	
	if (a > 0 && b == 0) 
	{
		Account alocalcustomer(a);
		customer = alocalcustomer;
	} 
	else if (a > 0 && b > 0)
	{
		Account anotherlocalcustomer(a,b);
		customer = anotherlocalcustomer;
	}
	customer.somefunction();
	return 0;
}

Which gives for examples following outputs depending on what u enter:

c++ Syntax (Toggle Plain Text)
//---------1st case :
please enter a value for a:
0
please enter a value for b:
-1
Initial balance is: 0
id is: 0
credit Limit is: 0
//---------2nd case :
please enter a value for a:
1
please enter a value for b:
0
Initial balance is: 100
id is: 1
credit Limit is: 500
//---------3rd case :
please enter a value for a:
2
please enter a value for b:
320
Initial balance is: 2
id is: 320
credit Limit is: 100
//---------1st case :
please enter a value for a:
0
please enter a value for b:
-1
Initial balance is: 0
id is: 0
credit Limit is: 0
//---------2nd case :
please enter a value for a:
1
please enter a value for b:
0
Initial balance is: 100
id is: 1
credit Limit is: 500
//---------3rd case :
please enter a value for a:
2
please enter a value for b:
320
Initial balance is: 2
id is: 320
credit Limit is: 100

sidatra79

Reputation Points: 46

Solved Threads: 8

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since Feb 2008

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Oct 10th, 2008

Re: [need help] Initializing Objects in Control Structures

It's a good idea but not so good implementation. No need to define assignment operator: it's exactly default assignment. Keep it simpler:

C++ Syntax (Toggle Plain Text)
Account customer;
...
if (a > 0 && b > 0)
   customer = Account(a,b);
customer.somefunction();
Account customer;
...
if (a > 0 && b > 0)
   customer = Account(a,b);
customer.somefunction();

ArkM

Reputation Points: 1234

Solved Threads: 347

Postaholic

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since Jul 2008

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Oct 10th, 2008

Re: [need help] Initializing Objects in Control Structures

For sure but it seemed to me, that he wanted to use the "some.function" outside the local scopes of the if statements while initializing objects there.

So I tried to give him such a solution.

Click to Expand / Collapse Quote originally posted by ArkM ...

It's a good idea but not so good implementation. No need to define assignment operator: it's exactly default assignment. Keep it simpler:
C++ Syntax (Toggle Plain Text)
Account customer;
...
if (a > 0 && b > 0)
   customer = Account(a,b);
customer.somefunction();
Account customer; ... if (a > 0 && b > 0) customer = Account(a,b); customer.somefunction();

sidatra79

Reputation Points: 46

Solved Threads: 8

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since Feb 2008

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Oct 11th, 2008

Re: [need help] Initializing Objects in Control Structures

Your problem is that the account objects are going out of scope when the if statement ends and their destructor's are being called. Initialized it outside of the if else statement and then just modify it as needed in the if statements. If you don't know what I mean by going out of scope just do a quick Google search. This is something every programmer should know about.

chunalt787

Reputation Points: 39

Solved Threads: 1

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since Apr 2008

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