Why is the 1st constructor being called, when I provoke the second one?

Question

I have the following class:

class Data
{
int* dat;
int csize;
Data(bool z=0 ,int cs=0)
{
cout<<"Default"<<endl;
dat = new int[100];
for(int i=0;i<cs;i++) dat[i]=0;
dat[0]=(z?0:1);
}
Data(string a)
{
cout<<"Special"<<endl;
csize = a.length();
dat =new int[a.length()];
for(int i=0;i<a.length();i++)
dat[i] = a.at(a.length()-i-1)-48;
}
friend ostream& operator<<(ostream&,Data);
};

Now, on calling the following in main:

Data d("23334");
cout<<d<<endl;

The program prints 0. Why?

Answer 1

The ostream operator works fine with the 1st constructor...
Also, I copy the size into a variable calles csize, in both constructors...

Answer 2

@Immortal
I had to erase it here, Thanks to SoloLearn's 512 char limit...

Answer 3

The complete class:

class Data
{
int* dat;
int csize;
Data(bool z=0 ,int cs=0)
{
cout<<"Default"<<endl;
csize = cs;
dat = new int[100];
for(int i=0;i<cs;i++) dat[i]=0;
dat[0]=(z?0:1);
}
Data(string a)
{
cout<<"Special"<<endl;
csize = a.length();
dat =new int[a.length()];
for(int i=0;i<a.length();i++)
dat[i] = a.at(a.length()-i-1)-48;
}
friend ostream& operator<<(ostream& os,Data d)
{
for(int i=csize-1;i>=0;i--)
os<<d.dat[i];
return os;
}
};

Answer 4

@Immortal
Yes, and this works, maybe as int can never hold a string, but bool may...

Answer 5

I interchanged the bool and the int parameters, and it started working...

So, can i conclude that bool can even analyze strings as true or false?

Thank You for answering!