voler | The first Bootstrap 5 admin dashboard template | Dashboard library

The problem was that the web page wasn't fully loaded before the click on the delete button. So I put a thread.sleep of 1000 ms to resolve it.

Correct code:

The input into verify is writing beyond the array bounds, overwriting other memory, among it your variable. Use std::string instead or at least increase the array size beyond the expected input length (and, for a safe program, protect against boundary violations!).

In more detail, the array argument is, as is the case in many contexts, "adjusted" to a pointer to char; this matches the istream& operator>> (istream& is, char* s). This operator copies a "word" from the standard input into the memory pointed to. It skips any whitespace (for example, the newline left behind from when you last hit the enter key) and then copies characters from stdin to the indicated memory location; it stops before the next whitespace in the input (for example, the newline produced when you hit the enter key to "finish your input"). After the input characters are written the routine terminates the entered 1-character "word" with a null character so that it is a proper "C string" after the crude fashion that was modern in 1978.

If you entered a one-character word, that null character gets written to memory adjacent to your 1-char array, in this case n_alunni. (You can verify that hypothesis by entering a number into n_alunni that is larger than 255, thus altering more bytes which will not be affected by the zero byte. On an intel architecture the new value of n_alunni after a one-character input should then be n_alunni & ~0xff; that is, the same as after the input with the lowest byte zeroed out).

As is often the case, using std::string for text is a safer way to handle unknown text. There is an istream& operator>> (istream& is, string& str) that works just like the char * overload, only safer.

It redirects to the first tab because you use javascript tabs with active class added to first tab. To resolve problem with tabs you need to change for each tabs nav to: ...