Programming Forums > Application Development > C++

Planet_EN · Sep 17th, 2005, 5:11 PM

Hello Everyone!

I made an array class, well I am confused about a few things:

* I've read memset fucntion in a tutorial, I used it to initialize the whole array at once is it ok?

* I want to add a check boundary, like the arrayclass and member fucntion should not accept any number greater than or lesser than index. Where should I add it, and how would I add it?

* Can I convert this array class to accept all kinds of data in one variable? How can I do this?

(Toggle Plain Text)

class IntArray{
	
	public:
	  	 int  addAllElements(void);
		 int  sumOfElements(const int, const int);
		 void defineElement(const int);
		 void initializeAll(void);
		 void initializeAllBy(const int);
		 void showElement(const int);	
		 void readElement(const int);
		 void sortElements(bool);
		 void showElement(const int I, char ch);

	private:
		 int	  size;
 		 int	  length;
		 int	  Element;
		 int	  *Array;
		 bool	  order;
};

void IntArray :: defineElement(const int I){

	length = abs(I);
	Array  = new int[length];
}

void IntArray :: initializeAll(void){

	memset(Array,0,(sizeof Array)*length);
	
}

void IntArray :: initializeAllBy(const int I){

	for(int z=0; z<length; z++)
		*(Array + z) = I;
}

void IntArray :: showElement(const int I){

	Element = abs(I);
	cout << *(Array + Element)
		 << endl;

}	

void IntArray :: showElement(const int I, char ch){

	Element = abs(I);
	cout << *(Array + Element)
		 << ch;

}

void IntArray :: readElement(const int I){
	
	Element = abs(I);
	cin >> *(Array + Element);

}

void IntArray :: sortElements(bool I){
	
	int swaper;
	Element = Array[0];

	if(I == 0) {
		for(int z=0; z<length; z++)
		{
			for(int y=0; y<length-1; y++)
			{
				if( Array[y] > Array [y+1] )
				{
					swaper     = Array[y];
					Array[y]   = Array[y+1];
					Array[y+1] = swaper;

				}

			}

		}
	
	}

	if(I == 1) {
		for(int z=0; z<length; z++)
		{
			for(int y=0; y<length-1; y++)
			{
				if( Array[y] < Array [y+1] )
				{
					swaper     = Array[y];
					Array[y]   = Array[y+1];
					Array[y+1] = swaper;

				}

			}

		}
	
	}

	else if( I != 1 && I != 0 )
	{
		cout << "Please enter 0 for ascending"
			    "or 1 for descending order sorintg";
	}


}

int IntArray :: addAllElements(void){

	for(int sum=0,z=0; z<length; z++)
		sum += Array[z];
	return (sum);
}

int IntArray :: sumOfElements(const int start, const int end){

	for(int sum=0,z=start; z<end; z++)
		sum += Array[z];
	return (sum);
	

}

DaWei · Sep 17th, 2005, 5:22 PM

If this isn't just a learning exercise (which would be a Good Thang, don't get me wrong), have you considered the STL and, maybe, templates?

Planet_EN · Sep 17th, 2005, 5:34 PM

Quote:

Originally Posted by DaWei

If this isn't just a learning exercise (which would be a Good Thang, don't get me wrong), have you considered the STL and, maybe, templates?

yes I know about STL and templates and I can use them to make my life alot easier, but I am more interested in making my own classes, and yeah this is for excercise.

bl00dninja · Sep 17th, 2005, 6:01 PM

haha...i got flamed once for suggesting that creating a vector class was a waste of time. more power to ya!!!

DaWei · Sep 17th, 2005, 6:28 PM

It's a waste of time if you're looking for commercial success instead of knowledge

. One picks and chooses

.

DaWei · Sep 17th, 2005, 6:58 PM

There's a high probability that it'll work fine (sizeof Array--a pointer--on a lot of systems is the same as sizeof int), but it's just serendipitous.

Planet_EN · Sep 18th, 2005, 12:51 AM

Well, what about my questions?

grumpy · Sep 18th, 2005, 1:41 AM

Quote:

Originally Posted by Planet_EN

Well, what about my questions?

As to your first question, you can use memset to initialise the array for your IntArray.

With your second question, on checking that indices are valid, you would add that check anywhere where you wish to get an element of the array (by index). I would probably create a member named ValidIndex(int index) or something similar, and call that wherever needed (and have that member return false if given an invalid index). An alternate strategy which will encourage users of your class to ensure they employ valid indices, would be a member function named ValidateIndex(int index) which throws an exception when the index is invalid. The choice of such approaches (or using both of them) depends on what you're trying to achieve.

Your third question is unclear. If your goal is to adapt your class so it can hold an array of anything, I'd rename it (eg to Array) and make it into a template class. That way you could have an Array<int> or an Array<double> or an Array<AnyOtherType>. One issue with doing that is that you will no longer be able to use memset() to initialise the array data (as using memset() simply writes data to raw memory, and does not play nicely when that memory actually refers to C++ objects that have constructors, destructors, or [especially] virtual member functions.

Planet_EN · Sep 18th, 2005, 5:11 AM

Quote:

Your third question is unclear. If your goal is to adapt your class so it can hold an array of anything, I'd rename it (eg to Array) and make it into a template class. That way you could have an Array<int> or an Array<double> or an Array<AnyOtherType>. One issue with doing that is that you will no longer be able to use memset() to initialise the array data (as using memset() simply writes data to raw memory, and does not play nicely when that memory actually refers to C++ objects that have constructors, destructors, or [especially] virtual member functions.

Is it possible by overloading? I do not want to use templates. Can you just tell me how to overload it for everytype?

grumpy · Sep 18th, 2005, 6:29 AM

Quote:

Originally Posted by Planet_EN

Is it possible by overloading? I do not want to use templates. Can you just tell me how to overload it for everytype?

Overloading is simply allowing multiple versions of a function, all with the same name, but with each version of the function taking arguments of different types.

If you want to do overloading for all possible types, the solution is to use a template function. That's one of the fundamental purposes of templates.

Why don't you want to use templates?

Sep 17th, 2005, 5:11 PM	#1
Planet_EN Programmer Join Date: Mar 2005 Posts: 40 Rep Power: 0	IntArray Class Hello Everyone! I made an array class, well I am confused about a few things: * I've read memset fucntion in a tutorial, I used it to initialize the whole array at once is it ok? * I want to add a check boundary, like the arrayclass and member fucntion should not accept any number greater than or lesser than index. Where should I add it, and how would I add it? * Can I convert this array class to accept all kinds of data in one variable? How can I do this? (Toggle Plain Text) class IntArray{ public: int addAllElements(void); int sumOfElements(const int, const int); void defineElement(const int); void initializeAll(void); void initializeAllBy(const int); void showElement(const int); void readElement(const int); void sortElements(bool); void showElement(const int I, char ch); private: int size; int length; int Element; int Array; bool order; }; void IntArray :: defineElement(const int I){ length = abs(I); Array = new int[length]; } void IntArray :: initializeAll(void){ memset(Array,0,(sizeof Array)length); } void IntArray :: initializeAllBy(const int I){ for(int z=0; z<length; z++) (Array + z) = I; } void IntArray :: showElement(const int I){ Element = abs(I); cout << (Array + Element) << endl; } void IntArray :: showElement(const int I, char ch){ Element = abs(I); cout << (Array + Element) << ch; } void IntArray :: readElement(const int I){ Element = abs(I); cin >> (Array + Element); } void IntArray :: sortElements(bool I){ int swaper; Element = Array[0]; if(I == 0) { for(int z=0; z<length; z++) { for(int y=0; y<length-1; y++) { if( Array[y] > Array [y+1] ) { swaper = Array[y]; Array[y] = Array[y+1]; Array[y+1] = swaper; } } } } if(I == 1) { for(int z=0; z<length; z++) { for(int y=0; y<length-1; y++) { if( Array[y] < Array [y+1] ) { swaper = Array[y]; Array[y] = Array[y+1]; Array[y+1] = swaper; } } } } else if( I != 1 && I != 0 ) { cout << "Please enter 0 for ascending" "or 1 for descending order sorintg"; } } int IntArray :: addAllElements(void){ for(int sum=0,z=0; z<length; z++) sum += Array[z]; return (sum); } int IntArray :: sumOfElements(const int start, const int end){ for(int sum=0,z=start; z<end; z++) sum += Array[z]; return (sum); } class IntArray{ public: int addAllElements(void); int sumOfElements(const int, const int); void defineElement(const int); void initializeAll(void); void initializeAllBy(const int); void showElement(const int); void readElement(const int); void sortElements(bool); void showElement(const int I, char ch); private: int size; int length; int Element; int Array; bool order; }; void IntArray :: defineElement(const int I){ length = abs(I); Array = new int[length]; } void IntArray :: initializeAll(void){ memset(Array,0,(sizeof Array)length); } void IntArray :: initializeAllBy(const int I){ for(int z=0; z<length; z++) (Array + z) = I; } void IntArray :: showElement(const int I){ Element = abs(I); cout << (Array + Element) << endl; } void IntArray :: showElement(const int I, char ch){ Element = abs(I); cout << (Array + Element) << ch; } void IntArray :: readElement(const int I){ Element = abs(I); cin >> (Array + Element); } void IntArray :: sortElements(bool I){ int swaper; Element = Array[0]; if(I == 0) { for(int z=0; z<length; z++) { for(int y=0; y<length-1; y++) { if( Array[y] > Array [y+1] ) { swaper = Array[y]; Array[y] = Array[y+1]; Array[y+1] = swaper; } } } } if(I == 1) { for(int z=0; z<length; z++) { for(int y=0; y<length-1; y++) { if( Array[y] < Array [y+1] ) { swaper = Array[y]; Array[y] = Array[y+1]; Array[y+1] = swaper; } } } } else if( I != 1 && I != 0 ) { cout << "Please enter 0 for ascending" "or 1 for descending order sorintg"; } } int IntArray :: addAllElements(void){ for(int sum=0,z=0; z<length; z++) sum += Array[z]; return (sum); } int IntArray :: sumOfElements(const int start, const int end){ for(int sum=0,z=start; z<end; z++) sum += Array[z]; return (sum); }

Sep 17th, 2005, 5:22 PM	#2
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	If this isn't just a learning exercise (which would be a Good Thang, don't get me wrong), have you considered the STL and, maybe, templates? __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Sep 17th, 2005, 6:01 PM	#4
bl00dninja Programming Guru Join Date: Oct 2004 Location: namespace std Posts: 1,246 Rep Power: 5	haha...i got flamed once for suggesting that creating a vector class was a waste of time. more power to ya!!! __________________ i put on my robe and wizard hat... Have you ever heard of Plato, Aristotle, Socrates?...Morons.

Sep 17th, 2005, 6:28 PM	#5
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	It's a waste of time if you're looking for commercial success instead of knowledge . One picks and chooses . __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Sep 17th, 2005, 6:58 PM	#6
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	There's a high probability that it'll work fine (sizeof Array--a pointer--on a lot of systems is the same as sizeof int), but it's just serendipitous. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Sep 18th, 2005, 12:51 AM	#7
Planet_EN Programmer Join Date: Mar 2005 Posts: 40 Rep Power: 0	Well, what about my questions?

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Programming Forums > Application Development > C++

IntArray Class