Newbie Site fault issue C++ -
i'm working on project create bank accounts , able deposit , withdraw. create 2 bank account , 2 people- 1 one stack , other on heap. should deposit , withdraw each twice , balance print name , id , account numbers. @ moment i'm believe site fault , reading or writing protected memory. i've left comments on think errors lie. appreciate help. thanks.
#include <iostream> #include <string> using namespace std; class bankaccount { private: double *balance; int *accountnumber; public: bankaccount(){//default constructor *balance = 0.0;/***this says access violation lies*/ *accountnumber = 0; } bankaccount(double bal, int acctnum){//constructor balance = new double(bal); accountnumber = new int(acctnum); } ~bankaccount() {delete balance; delete accountnumber;} void deposit(double amt) { *balance = *balance + amt; } virtual double getbalance() { return *balance; } virtual double getaccountnumber() { return *accountnumber; } virtual double withdraw(double amt) { *balance = *balance - amt; return *balance; } }; class person { string *name; int *id; public: person(){//default constructor *name = "name not yet defined"; *id = 0; } person(string namein, int idin){//constructor name = new string(namein); id = new int(idin); } virtual int getid() { return *id; } virtual string getname() { return *name; } }; class namedbankaccount: public bankaccount { private: person *owner; public: namedbankaccount(){ } namedbankaccount(person *p): owner(p){/***this says access violation lies*/ p = new person(); } ~namedbankaccount(){delete owner;} person getperson() { return *owner; } }; int main() { person *q = new person("joe", 54321); cout << q->getname() << endl; cout << q->getid() << endl; namedbankaccount nba1;/***this says access violation lies*/ namedbankaccount *nba2 = new namedbankaccount(q); nba1.deposit(50); nba1.deposit(50); nba1.withdraw(25); cout << nba1.getbalance() <<endl;//should print 75 nba2->deposit(60); nba2->deposit(60); nba2->withdraw(20); cout << nba2->getbalance() << endl;//should print 100 getchar(); return 0; }
do not use pointers here. have strings , integers member variables. specific problem - haven't allocated memory before assignment in default constructor.
do like:
class bankaccount { private: double balance; int accountnumber; public: bankaccount() : balance( 0.0 ), accountnumber( 0 ) {} // ... edit:
couple of more points code:
- make use of initialization list in constructors instead of assignment member variables - avoids two-step process of first default-initializing members , assigning them
- base polymorphic classes should have
virtualdestructors, instances of derived classes destroyed via pointer base - polymorphic types need follow the rule of three avoid slicing
- do not make member functions of base class
virtual, want derived classes override - think before making type polymorphic - have bank accounts without owners? maybe can value type?
- make accessor methods
const, can informationconstinstances - check errors (you sure don't want allow withdrawals 0 or negative balance accounts)
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