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Type casting

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Join Date: Aug 2005

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Re: Type casting

#11

Oct 19th, 2005

If you had coded it like this, it would have worked. The constructor without parameters is never used in this example.

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include<iostream>
using namespace std;
class A
{
	int a;
	float b;
public:
	A()
	{
		a=0;
		b=0;
	}
	A(int m)
	{
		a=m;
		b=0;
		cout<<"values are "<<a<<endl<<b<< endl;
	}
};
int main()
{
	A a1(1);
	return 0;	
}
#include<iostream>
using namespace std;
class A
{
	int a;
	float b;
public:
	A()
	{
		a=0;
		b=0;
	}
	A(int m)
	{
		a=m;
		b=0;
		cout<<"values are "<<a<<endl<<b<< endl;
	}
};
int main()
{
	A a1(1);
	return 0;	
}

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Re: Type casting

#12

Oct 19th, 2005

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Originally Posted by Ancient Dragon

If you had coded it like this, it would have worked. The constructor without parameters is never used in this example.

As i said earlier it would work earlier also...just try to run that code...but b will have garbage value since you are not assigning any value to it...just read my above replies

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Re: Type casting

#13

Oct 20th, 2005

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Originally Posted by aminura

Now I am little confused...since constructors don't return any value how does type casting using parameterised constructors work. Like in the program a1=1; calls the constructor and value of a and b changes accordingly in the actual object..how does this happen?

I already answered that in my second reply....

a1=1.....automatically calls argument constructor and assign values to a and b....and then default assignment operator(=) supplied by compiler assigns these value to object a1.....according to your code a get value 1 and b contains garbage value...and the same is assigned to object a1....see this modified code

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include<iostream>
using namespace std;
class A
{
	int a;
	float b;
public:
	A()
	{
		a=0;
		b=0;
	}
	A(int m)
	{
		cout<<"Argument constructor getting called";
		a=b=m;
		cout<<"\n values are"<<a<<endl<<b;
	}
	void display()
	{
		cout<<"\nvalue of a:"<<a<<"  "<<"value of b:"<<b;
	}
};
void main()
{
	A a1;
	a1=1;
	a1.display();
 
}
#include<iostream>
using namespace std;
class A
{
	int a;
	float b;
public:
	A()
	{
		a=0;
		b=0;
	}
	A(int m)
	{
		cout<<"Argument constructor getting called";
		a=b=m;
		cout<<"\n values are"<<a<<endl<<b;
	}
	void display()
	{
		cout<<"\nvalue of a:"<<a<<"  "<<"value of b:"<<b;
	}
};
void main()
{
	A a1;
	a1=1;
	a1.display();
	
}

I suggest you to read a bit more about operator overloading and explicit keyword......and i think you could not understood(fully) the previous thread you started......