ios operator !() function in C++ with Examples Last Updated : 02 Sep, 2019 Comments Improve Suggest changes Like Article Like Report The operator!() method of ios class in C++ is used to any error flag of this stream is set. This includes the failbit or the badbit. Syntax: bool operator!() const; Parameters: This method does not accept any parameter. Return Value: This method returns true if any error bit is set of this stream, else false. Example 1: CPP // C++ code to demonstrate // the working of operator!() function #include <bits/stdc++.h> using namespace std; int main() { // Stream stringstream ss; // Using operator!() function if (!ss) { cout << "Error bit is set.\n"; } else { cout << "No error bit is set.\n"; } return 0; } Output: No error bit is set. Example 2: CPP // C++ code to demonstrate // the working of operator!() function #include <bits/stdc++.h> using namespace std; int main() { // Stream stringstream ss; ss.clear(ss.failbit); // Using operator!() function if (!ss) { cout << "Error bit is set.\n"; } else { cout << "No error bit is set.\n"; } return 0; } Output: Error bit is set. Reference: hhttp://www.cplusplus.com/reference/ios/ios/operator!/ Comment More infoAdvertise with us Next Article ios operator !() function in C++ with Examples G guptayashgupta53 Follow Improve Article Tags : Misc C++ CPP-Functions cpp-ios Practice Tags : CPPMisc Similar Reads ios operator() function in C++ with Examples The operator() method of ios class in C++ is used to any error flag of this stream is set. This includes the failbit or the badbit. Syntax: operator void*() const; Parameters: This method does not accept any parameter. Return Value: This method returns a null pointer if any error bit is set of this 1 min read ios operator() function in C++11 with Examples The operator() method of ios class in C++11 is used to any error flag of this stream is set. This includes the failbit or the badbit. Syntax: explicit operator bool() const; Parameters: This method does not accept any parameter. Return Value: This method returns false if any error bit is set of this 1 min read ios rdstate() function in C++ with Examples The rdstate() method of ios class in C++ is used to read the internal state of this stream. Syntax: iostate rdstate() const; Parameters: This method does not accept any parameter. Return Value: This method returns the current internal state of this stream. Example 1: CPP // C++ code to demonstrate / 1 min read ios bad() function in C++ with Examples The bad() method of ios class in C++ is used to check if the stream is has raised any bad error. It means that this function will check if this stream has its badbit set. Syntax: bool bad() const; Parameters: This method does not accept any parameter. Return Value: This method returns true if the st 1 min read ios eof() function in C++ with Examples The eof() method of ios class in C++ is used to check if the stream is has raised any EOF (End Of File) error. It means that this function will check if this stream has its eofbit set. Syntax: bool eof() const; Parameters: This method does not accept any parameter. Return Value: This method returns 1 min read norm() function in C++ with Examples The norm() function is defined in the complex header file. This function is used to return the squared magnitude of the complex number z. Syntax: template<class T> T norm (const complex<T>& z); Parameter: z: It represents the given complex number. Return: It returns the squared magni 1 min read ios good() function in C++ with Examples The good() method of ios class in C++ is used to check if the stream is good enough to work. It means that this function will check if this stream has raised any error or not. Syntax: bool good() const; Parameters: This method does not accept any parameter. Return Value: This method returns true if 1 min read ios fail() function in C++ with Examples The fail() method of ios class in C++ is used to check if the stream is has raised any fail error. It means that this function will check if this stream has its failbit set. Syntax: bool fail() const; Parameters: This method does not accept any parameter. Return Value: This method returns true if th 1 min read ios clear() function in C++ with Examples The clear() method of ios class in C++ is used to change the current state of the specified flag by setting it. Hence this function changes the internal state of this stream. Syntax: void clear(iostate state) Parameters: This method accepts the iostate as parameter which is the flag bit to be set in 2 min read log2() function in C++ with Examples The function log2() of cmath header file in C++ is used to find the logarithmic value with base 2 of the passed argument. Syntax: log2(x) Parameters: This function takes a value x, in the range [0, ∞] whose log value is to be found. Return Type: It returns the logarithmic value, as double, flo 2 min read Like