Im trying to write a simple code in c++ to read in integer from a text file, the code should stop reading when it encounter a negative integer. The txt file contains 1 positive integer on each line, and the last line is a negative integer.
My code right now using eof, and it reads in negative integer also, which I dont want.
while(!inFile.eof()) { inFile >> data; } Text file
10 22 33 34 -1 Thanks in advance :)
hmm..
int data = 0; while(inFile >> data && data >= 0) { // do stuff with data. } 
while (!eof) only for style reasons, for example.You would at least need to read the negative number to determine that you have reached end of input.
while( inFile >> data) { if ( data < 0 ) break; } 
istream::eof() as a loop condition, the code is almost certainly wrong.)istream::eof() was an error in the original code, and this should be pointed out. (Otherwise, Nim's answer is perfect.)while(!infile.eof()) { infile>>data; if(data>0) cout<<data; } read from the file check if it is greater than zero then print it
Maybe something like this, which tries to test the incoming integer, would work:
while(!inFile.eof()) { inFile >> data; if ( data < 0 ) { break; } } 
inFile >> data; but will be set after this call. When it is set you still use data even though the valu is now basically random. Rember the last successful read will read up-to but not past the EOF. The last read will attempt to read past and fail (at which point you can't use the value you were reading into).