Question

This C++ code, can someone create notes for this and break down what each line means line by line?

int readFloatMap(string fileName, double arr[][4], int rows) {
ifstream f(fileName.c_str());

if(f.fail()) {
return -1;
}

double a, b, c, d;

int r = 0;
while((r < rows) && (f >> a >> b >> c >> d)) {
arr[r][0] = a;
arr[r][1] = b;
arr[r][2] = c;
arr[r][3] = d;
r++;
}

return r; // success
}

Answer 1

int readFloatMap(string fileName, double arr[][4], int rows) {
ifstream f(fileName.c_str()); // read file from the memory

if(f.fail()) {
// if file does not load in to the memory due to any reason fail() will return true
return -1;
}

double a, b, c, d; // declare variables
int r = 0;

// f >> a >> b >> c >> d the input will come from file insted of keyboard
while((r < rows) && (f >> a >> b >> c >> d)) {
// while the input in not null get the input from file and save it into a, b, c, d.
// set the values of the matrix to a, b, c, d.
arr[r][0] = a;
arr[r][1] = b;
arr[r][2] = c;
arr[r][3] = d;
r++; // increment the row number
}

return r; // success
}

Image :

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