I placed "AAPL.csv" into the MetaTrader terminal folder's Files subfolder (MQL4/Files) to be accessible by the EA. The structure of this csv is as follows:
I want to read this, as well as many other similar csv files. All files have different lengths. My question is, what is the best practice when reading variable-length files? For now, I managed to read the content of my file by creating a 2-dimensional array:
although this is poor programming (what if the file only has 500 rows?) and it can still fail if I encounter a csv that is longer (what if file has 1000001 rows?). I tried using a dynamic array:
but it returns '[' - invalid index value error. Yet another idea I had to use the FileSize() function and allocate just-the-necessary amount of memory to the 2-dimensional array. However,
yielded a size that equals the product of column numbers and row numbers. I was hoping to obtain a row_count and col_count and use them to define s:
My full working code:
Inserted Code
Date,Open,High,Low,Close,Adj Close,Volume 1980-12-12,0.1283479928970337,0.1289059966802597,0.1283479928970337,0.1283479928970337,0.10092189908027649,469033600 1980-12-15,0.12221000343561172,0.12221000343561172,0.12165199965238571,0.12165199965238571,0.09565676748752594,175884800
I want to read this, as well as many other similar csv files. All files have different lengths. My question is, what is the best practice when reading variable-length files? For now, I managed to read the content of my file by creating a 2-dimensional array:
Inserted Code
string s[7][1000000];
Inserted Code
string s[7][];
Inserted Code
int handle=FileOpen(FileName,FILE_CSV|FILE_READ,",");
if(handle>0)
{
int size = FileSize(handle);
... Inserted Code
string s[col_count][row_count];
Inserted Code
extern string FileName = "AAPL.csv";
int init()
{
int row=0,col=0;
string s[7][1000000];
ResetLastError();
int handle=FileOpen(FileName,FILE_CSV|FILE_READ,",");
if(handle>0)
{
//int size = FileSize(handle);
//Print(size);
while(True)
{
string temp = FileReadString(handle);
if(FileIsEnding(handle)) break; //FileIsEnding = End of File
s[col][row]=temp;
if(FileIsLineEnding(handle)) //FileIsLineEnding = End of Line
{
col = 0; //reset col = 0 for the next row
row++; //next row
}
else
{
col++; //next col of the same row
}
}
FileClose(handle);
}
else
{
Comment("File "+FileName+" not found, the last error is ", GetLastError());
}
return(0);
}
int start()
{
return(0);
}
//+------------------------------------------------------------------+ 
