std::iomanip c++

std::iomanip is a header file in the C++ Standard Library that provides several functions and manipulators to control the format of input and output in C++.

The "std::" prefix indicates that the functions and manipulators defined in the iomanip header file are part of the standard namespace in C++. The "iomanip" part of the header file name stands for "input/output manipulators."

The iomanip header file allows you to control the formatting of various types of input and output operations, such as setting the precision of floating-point numbers, aligning text, setting the width of output fields, and manipulating the format of numeric values.

By including the iomanip header file in your C++ program, you can access various functions and manipulators defined in it. These functions and manipulators can be used to modify the behavior of input and output streams, such as std::cout and std::cin.

Some commonly used manipulators provided by std::iomanip include:

• std::setw: Sets the width of the output field. For example, std::cout << std::setw(10) << "Hello" will output " Hello" with a field width of 10.

• std::setprecision: Sets the precision (number of decimal places) for floating-point numbers. For example, std::cout << std::setprecision(2) << 3.14159 will output "3.14" with a precision of 2.

• std::setfill: Sets the fill character for output fields. For example, std::cout << std::setfill('') << std::setw(10) << "Hello" will output "*Hello" with a fill character of ''.

• std::left and std::right: Controls the alignment of output fields. For example, std::cout << std::setw(10) << std::left << "Hello" will output "Hello " with left alignment.

These are just a few examples of the functions and manipulators provided by std::iomanip. By including this header file and using its functions and manipulators, you can have greater control over the formatting of input and output in your C++ programs.