The C++ ostream class provides a set of functions and operators for writing data as output.
Before using ostream, we need to include the <iostream> header in our program.
#include <iostream> C++ Insertion Operator <<
To write data to the console using ostream, we can use the cout object with the insertion operator << operator.
#include <iostream> using namespace std; int main() { int entered_number; // write the text "Hello World!" to the screen cout << "Hello World!"; return 0; } Output
Hello World!
C++ put() Function
The put() function of ostream is primarily used to write characters to the console. For example,
#include <iostream> using namespace std; int main() { char ch = 'A'; // print a character to the console cout.put(ch); cout<< endl ; // print another character to the console cout.put('C'); return 0; } Output
A C
C++ write() Function
The write() function of ostream is generally used to write blocks of data into the console. For example,
#include <iostream> #include <cstring> using namespace std; int main() { // create a C-string const char* str = "Hello, World!"; // print the C-string cout.write(str, strlen(str)); return 0; } Output
Hello, World!
Here, we have written a C-string Hello, World to the output stream using the write() function.
Note: We have used a C-string with the write() function because it doesn't work with std::string objects of C++.