From cppreference.com
booleof()const;Returns true if the associated stream has reached end-of-file. Specifically, returns true if eofbit is set in
.
See
for the list of conditions that set eofbit.
Parameters
(none)
Return value
true if an end-of-file has occurred, false otherwise.
Notes
This function only reports the stream state as set by the most recent I/O operation; it does not examine the associated data source. For example, if the most recent I/O was a
which returned the last byte of a file, eof() returns false. The next get() fails to read anything and sets the eofbit. Only then does eof() return true.
In typical usage, input stream processing stops on any error. eof() and
can then be used to distinguish between different error conditions.
Example
Run this code
#include<cstdlib>#include<fstream>#include<iostream>intmain(){std::ifstreamfile("test.txt");if(!file)// operator! is used here{std::cout<<"File opening failed\n";returnEXIT_FAILURE;}// typical C++ I/O loop uses the return value of the I/O function// as the loop controlling condition, operator bool() is used herefor(intn;file>>n;)std::cout<<n<<' ';std::cout<<'\n';if(file.bad())std::cout<<"I/O error while reading\n";elseif(file.eof())std::cout<<"End of file reached successfully\n";elseif(file.fail())std::cout<<"Non-integer data encountered\n";}See also
The following table shows the value of
accessors (
,
, etc.) for all possible combinations of
flags:
flags basic_ios accessors eofbitfailbitbadbit
false false false true false false false true false false false true false true true false false true false true false false true false false false true false true true false true true false false true true false false false false false true true false true false true false true true true false true true true false false true false true false true true true true false true true true false true