Dynamic memory allocation

[Reannah]

i have a class as below

class Test
{
	int m_nNum;
public:
	Test( int nNum_i )
	{
		m_nNum = nNum_i;
	}
	
};

is there anyway to create a dynamic array of 10 Test Objects. remember Test has no default constructor. I need to get something like

Test* TObj = 0;
TObj = new Test[200];

it would be enough if i could at least static array.pls help

[Athar]

For a static array, you can do this:
Test array[200]={3,1,4,1,5...};

[Reannah]

Athar, it will not work.

[PiMaster]

Couldn't you just make a constructor with no parameters, and fill in the variables after declaration? Example:

class Test
{
	int m_nNum;
public:
	Test( int nNum_i )
	{
		m_nNum = nNum_i;
	}
	Test()
	{
	// initialize variables that
	// don't require arguments
	}
	setvars( int nNum_i )
	{
	m_nNum=nNum_i;
	}
};

[helios]

No, there's no way to pass constructor parameters to objects constructed as part of dynamically allocated arrays.

[Athar]

Reannah wrote:

Athar, it will not work.

It will.

[rahulroot]

if you change your Test constructor to this.

Test(int nNum_i=0)
{
m_nNum = nNum_i;
}

it is default constructor with default argument,it will solve 2 purposes,it can use to construct object using dynamically allocated memory or simple object with arguments or withour arguments also.

hope this will solve ur problem.

[ne555]

You could reserve the memory and later construct the elements (one by one).

//allocator<Test> aux;
//Test *const array = aux.allocate(n);//reserve a block of memory 
Test *const array =(Test *) malloc( sizeof(Test)*n );

//construct 1 object
//new ((void*)(array+i)) Test(value);
new (array+i) Test(value);

Or use Test **, or an STL container