Dynamic Memory Allocation

[Atomic_Sheep]

Hi Guys,

Just trying to figure out how to use dynamic memory allocation. I've got the following program:

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
 
    char *cText;
    cText = new char[5];
    cText = "test11111";
 
    qDebug() << cText;
 
    delete[] cText;
 
    return a.exec();
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    char *cText;
    cText = new char[5];
    cText = "test11111";

    qDebug() << cText;

    delete[] cText;

    return a.exec();
}

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Question is... why does it let me assign a string of more than 5 characters to this memory location?

[wysota]

You are assigning a value to the pointer, not to the char array behind the pointer. Your code is equivalent to:

int main() {
char *cText = 0;   // line #5
char *ptr1 = "test11111"; // line #7
char *ptr2 = new char[5]; // line #6
 
cText = ptr2; // line #6
cText = ptr1;  // line #7
delete [] ptr1; // line #11
// cText points to ptr1 and not ptr2
}

int main() {
char *cText = 0;   // line #5
char *ptr1 = "test11111"; // line #7
char *ptr2 = new char[5]; // line #6

cText = ptr2; // line #6
cText = ptr1;  // line #7
delete [] ptr1; // line #11
// cText points to ptr1 and not ptr2
}

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[Atomic_Sheep]

Got it to work thanks.