basic_istream::putback() in C++ with Examples Last Updated : 28 May, 2020 Comments Improve Suggest changes Like Article Like Report The basic_istream::putback() used to put the character back in the input string. This function is present in the iostream header file. Below is the syntax for the same: Header File: #include<iostream> Syntax: basic_istream& putback (char_type ch); Parameter: ch: It represents the character to be put into the input string back. Return Value: The iostream::basic_istream::putback() return the basic_istream object. Below are the programs to understand the implementation of std::basic_istream::putback() in a better way: Program 1: CPP14 // C++ code for basic_istream::putback() #include <bits/stdc++.h> using namespace std; int main() { stringstream gfg1("GeeksforGeeks"); gfg1.get(); // putback A into the input string if (gfg1.putback('A')) cout << gfg1.rdbuf() << endl; istringstream gfg2("GeeksforGeeks"); gfg2.get(); if (gfg2.putback('A')) cout << gfg2.rdbuf() << endl; else cout << "putback is failed here\n"; gfg2.clear(); // Again putback G in the string if (gfg2.putback('G')) cout << gfg2.rdbuf() << endl; } Output: AeeksforGeeks putback is failed here GeeksforGeeks Program 2: CPP14 // C++ code for basic_istream::putback() #include <bits/stdc++.h> using namespace std; int main() { stringstream gfg1("GOOD"); gfg1.get(); // putback B into the input string if (gfg1.putback('B')) cout << gfg1.rdbuf() << endl; istringstream gfg2("GOOD"); gfg2.get(); if (gfg2.putback('B')) cout << gfg2.rdbuf() << endl; else cout << "putback is failed here\n"; gfg2.clear(); // Again putback G in the string if (gfg2.putback('G')) cout << gfg2.rdbuf() << endl; } Output: BOOD putback is failed here GOOD Reference: http://www.cplusplus.com/reference/istream/istream/putback/ Comment More infoAdvertise with us Next Article basic_istream::putback() in C++ with Examples B bansal_rtk_ Follow Improve Article Tags : Misc C++ CPP-Functions Practice Tags : CPPMisc Similar Reads basic_istream::peek() in C++ with Examples The std::basic_istream::peek() used to reads the next character from the input stream without extracting it. This function does not accept any parameter, simply returns the next character in the input string. Below is the syntax for the same: Header File: #include<iostream> Syntax: int peek(); 2 min read basic_istream::unget() in C++ with Examples The basic_istream::unget() is used to unget the character and used to decrease the location by one character and makes the extracted character available for used once again. Header File: <iostream> Syntax: basic_istream& unget(); Parameters: The basic_istream::unget() method doesn’t accept 2 min read basic_istream::swap() in C++ with Examples The basic_ios::swap(x) is used swap all data members of the base class except for rdbuf(), and swaps the values of the gcount() counters between *this and x. This basic_ios::swap(x) function is a protected function. Below is the syntax and the header file for the same: Header File: #include<iostr 2 min read basic_istream::seekg() in C++ with Examples The basic_stream::seekg() method is used to set position of the next character to be extracted from the input stream. This function is present in the iostream header file. Below is the syntax for the same: Header File: #include<iostream> Syntax: basic_istream& seekg (pos_type pos); Paramet 2 min read basic_istream::get() in C++ with Examples The basic_istream::get() is used to get the character. This function returns a one character if available, otherwise it will return end of the file. Header File: <iostream> Syntax: int_type get(); Parameters: The method basic_istream::get() doesn’t accept any parameter. Return Value: The metho 2 min read Like