C++ Tutorial: Standard Manipulators
It is seen that for formatted input/output the stream class ios function are used. To call ios function for formatting, we need to write separate statement and call the function through stream objects cin and cout. Manipulators are the formatting function for input/output that are embedded directly into the C++ input/output statements so that extra statements are not required. Manipulators are used along with the extraction >> and insertion << operators for stream input and output formatting. According to the number of arguments to be supplied manipulators are categorized in the following types.
- Non-parameterized Manipulators
- Parameterized Manipulators
Non parameterized Manipulators do no take argument to control the formatting of input/output where as parameterized manipulators take argument for formatting. The Following table shows different non parameterized manipulators.
| Manipulator | Effect produced |
| left | sets ios::left flag of ios::adjustfield |
| right | sets ios::right flag of ios::adjustfield |
| internal | sets ios::internal flag of ios::adjustfield |
| dec | sets ios::dec flag of ios::adjustfield |
| hex | sets ios::hex flag of ios::adjustfield |
| oct | sets ios::oct flag of ios::adjustfield |
| scientific | sets ios::scientific flag of ios::floatfield |
| fixed | sets ios::fixed flag of ios::floatfield |
| showbase | sets ios::showbase flag |
| noshowbase | resets ios::showbase flag |
| showpoint | sets ios::showpoint flag |
| noshowpoint | resets ios::showpoint flag |
| showpos | sets ios::showpos flag |
| noshowpos | resets ios::showpos flag |
| uppercase | sets ios::uppercase flag |
| nouppercase | resets ios::uppercase flag |
| skipws | sets ios::skipws flag |
| noskipws | resets ios::skipws flag |
| boolalpha | sets ios::boolalpha flag |
| noboolalpha | resets ios::boolalpha flag |
| unitbuf | sets ios::unitbuf flag |
| nounitbuf | resets ios::unitbuf flag |
| endl | output newline and flush |
| ends | ouput ‘ ’ character |
| flush | flush the stream, same as ostream::flush |
| ws | removes all white space from input stream until non white space character. |
Following table shows different parameterized manipulators
| Manipulators | Effect produced |
| setw(int n) | equivalent to ios function width() |
| setprecision (int n) | equivalent to ios function precision() |
| setfill(int c) | equivalent to ios::function fill() |
| setbase (int b) | sets base for integer output, argument 0 is passed for decimal, 8 or octal, 10 for decimal and 16 for hexadecimal. |
| setiosflags(ios::fmtflags f) | equivalent to ios function setf() |
| resetiosflags(ios::fmtflags f) | equivalent to ios function unsetf() |
