Loop: Compiles ok, crashes when run

Question

Aim = count lines in the file

Code within loop that crashes:
_____________________________________
while (file.get(read)){

if (read=='\n') {
cout << line_number << endl;
line_number++; //when i try to increase line_number it compiles, however when i run the programm windows stops it.

}
______________________

full function code:
_______________________________
int convert_to_array (char *pFileName) {
char read;
string sRead;
fstream file(pFileName,ios::in);
int aLength,line_number;
string array[aLength];
if (file.is_open()) {
cout << "file again opened " << pFileName<<endl;
line_number = 1;
while (file.get(read)){

if (read=='\n') {
cout << line_number << endl;
line_number++; //when i try to increase line_number it compiles, however when i run the programm windows stops it.

}

sRead=sRead+read;
cout << sRead << flush;
sRead.clear();
}

file.close();

}

}

Answer 1

Hi George,

The problem is in the line you define "string array[aLenght]". Notice that you did not initialize the variable aLenght, thus it stores trash which can be any value even negative.
Therefore you are trying to create a variable string with undetermined size. Either you declare something like "string array[1024]", i.e., a constant value or use dynamic memory allocation.

Here is a working code:
https://code.sololearn.com/cwmIRzLNRvXP/?ref=app

Answer 2

thank you very much Mark! Works!
i've crunched my brain on this :)

what is interesting is that code worked even with this declaration:
string array[aLength]; (if you just put line_number; it works, problems started when increment "++" appeared)

again many thanks to you!