what is line 5 doing?

[enemy]

Please, how did it come to line 5? What commands cause wrirting it out???

many thanks

  int* po(int b){
int d1;
d1=3*b;
int d2;
d2=d1+5;
int a[3];
a[0]=d1;
a[1]=d2;
a[2]=a[1]+3;
int* p=a;
cout<<"po: "<<p<<endl;
return p;
}


int main(){
int st=4;
cout<<" main: "<<po(st)<<"xx"<<endl<<endl<<endl;
int* h;
h=po(st);
cout<<endl;
cout<<"main: "<<*h<<endl;
return 0;
}

[keskiverto]

What do you mean by "line 5"?

Local array a[3] does not exist outside of the scope of the functio 'po' and therefore returning the address of the array is an error.

[enemy]

Hello!
I am getting this:

po: 0xbf57cff4
 main: 0xbf57cff4xx


po: 0xbf57cff4

main: 12

This 5th line is what i do not see its cause...!

It is obviously after line 18 is being executed, and BEFORE line 22 is executed...:roll???

[keskiverto]

You get first "po:" from calling the po() on line 18, the first " main:" on line 18, the second "po:" from second call of po() on line 20, and the second "main:" on line 22.

[enemy]

sure, but is line 20 supposed to cout it? That is confusing me!

many thnks!

[keskiverto]

Supposed? How could we know? It is your function po() that prints something on its line 11. You should know what your code is supposed to do.

[enemy]

Hello!
Line 11 causes the line 1 in executing.
Then: line 18 causes line 2 and 2 empty lines after it.(lines 3 and 4).

Then: U said line 20 causes line 5, but I do not understand this part.

Then: line 21 causes free line 6.
Then: line 22 causes line 7.


So: all clear, except line 21 causing line 5).

If I wanted var h not to be cout-ed, (but only *h), how should I write the code?
Many thanks!

[keskiverto]

You do call function po() twice. Function po() prints a line. Therefore, line is printed two times.

Solution: You either do not call the function multiple times or the function does not print a line.


However, like I said the first time, the rest of your code leads to undefined results and should be changed.

[enemy]

Hello!
I am working in codepad (http://codepad.org/), and I am NOT GETTING any undefined results.

I pasted the complete output under the code.

Now, look, line 20 h=po(st); definitiveljy COUTS the po*().

But, if I don't want it to be couted, but only *h, how to write it?


Many thanks!

[keskiverto]

I wrote:

Solution: ...

Note: Undefinded, by definition, can be anything. It can even look like the expected, valid result in some conditions, but that is just a fluke.