C++ defines some format flags for standard input and output, which can be manipulated
with the
flags(), setf(), and
unsetf() functions. For example,
Flag | Meaning |
boolalpha | Boolean values can be input/output using the words "true" and
"false". |
dec | Numeric values are displayed in decimal. |
fixed | Display floating point values using normal notation (as opposed to
scientific). |
hex | Numeric values are displayed in hexidecimal. |
internal | If a numeric value is padded to fill a field, spaces are inserted between
the sign and base character. |
left | Output is left justified. |
oct | Numeric values are displayed in octal. |
right | Output is right justified. |
scientific | Display floating point values using scientific notation. |
showbase | Display the base of all numeric values. |
showpoint | Display a decimal and extra zeros, even when not needed. |
showpos | Display a leading plus sign before positive numeric values. |
skipws | Discard whitespace characters (spaces, tabs, newlines) when reading from a
stream. |
unitbuf | Flush the buffer after each insertion. |
uppercase | Display the "e" of scientific notation and the "x" of hexidecimal notation
as capital letters. |
Manipulators defined in <iostream> |
Manipulator | Description | Input | Output |
boolalpha | Turns on the boolalpha flag | X | X |
dec | Turns on the dec flag | X | X |
endl | Output a newline character, flush the stream | | X |
ends | Output a null character | | X |
fixed | Turns on the fixed flag | | X |
flush | Flushes the stream | | X |
hex | Turns on the hex flag | X | X |
internal | Turns on the internal flag | | X |
left | Turns on the left flag | | X |
noboolalpha | Turns off the boolalpha flag | X | X |
noshowbase | Turns off the showbase flag | | X |
noshowpoint | Turns off the showpoint flag | | X |
noshowpos | Turns off the showpos flag | | X |
noskipws | Turns off the skipws flag | X | |
nounitbuf | Turns off the unitbuf flag | | X |
nouppercase | Turns off the uppercase flag | | X |
oct | Turns on the oct flag | X | X |
right | Turns on the right flag | | X |
scientific | Turns on the scientific flag | | X |
showbase | Turns on the showbase flag | | X |
showpoint | Turns on the showpoint flag | | X |
showpos | Turns on the showpos flag | | X |
skipws | Turns on the skipws flag | X | |
unitbuf | Turns on the unitbuf flag | | X |
uppercase | Turns on the uppercase flag | | X |
ws | Skip any leading whitespace | X | |