Streams are like flexible flow-through containers.


#include <iostream>



int main()

{

  const bool b = true;

  const char c = 'c';

  const int i = 1;

  const double d = 1.1;

  std::cout

    << "bool b: " << b << '\n'

    << "char c: " << c << '\n'

    << "integer i: " << i << '\n'

    << "double d: " << d << std::endl;

}

Screen output:


bool b: 1

char c: c

integer i: 1

double d: 1.1

stream operations

Things one can do on a stream:

std::endl: adds newline ('\n') and flushes the stream
std::ends: adds null ('\0') to the stream

Stream format flags

A stream format flag is something that can be on or off. Stream format flags are:

std::ios::skipws: skip whitespace (on by default for input streams)
std::ios::showbase: indicate the numeric base
std::ios::showpoint: show decimal point and trailing zeroes for doubles
std::ios::uppercase: show uppercase characters in hex (ABCDEF) and scientific (E) notation
std::ios::showpos
std::ios::unitbuf

Turning a flag on and off is shown in the code below.


#include <iostream>



int main()

{

  std::cout << 1 << '\n';

  std::cout.setf(std::ios::showpos);

  std::cout << 1 << '\n';

  std::cout.unsetf(std::ios::showpos);

  std::cout << 1 << '\n';

}

Stream flag field

A stream flag field is a group of options of which only one can be in effect, similar to a radiogroup control. To set a certain option, one needs to clear the flag group field, then set the desired option.

Stream format flags are:

std::ios::basefield: std::ios::dec, std::ios::hex, std::ios::oct
std::ios::floatfield: std::ios::fixed, std::ios::scientific
std::ios::adjustfield: std::ios::left, std::ios::right, std::ios::internal


#include <iostream>



int main()

{

  //Turns on decimal notation,

  //clears current notation (i.e. basefield)

  std::cout.setf(std::ios::dec,std::ios::basefield);

  std::cout << 15 << '\n';

  //Turns on hexadecimal notation,

  //clears current notation (i.e. basefield)

  std::cout.setf(std::ios::hex,std::ios::basefield);

  std::cout << 15 << '\n';

  //Turns on octal notation,

  //clears current notation (i.e. basefield)

  std::cout.setf(std::ios::oct,std::ios::basefield);

  std::cout << 15 << '\n';

}

Stream manipulators

Stream manipulators are like stream formatting flags and formatting fields, except that manipulators are the streamable version of flags and fields.

Stream manipulators are:


#include <iostream>



int main()

{

  //Turn on decimal notation

  std::cout << std::dec << 15 << '\n';

  //Turn on hexidecimal notation

  std::cout << std::hex << 15 << '\n';

  //Turn on octal notation

  std::cout << std::oct << 15 << '\n';

}

stream code snippets

Some code snippets one can use when working witj stream:

Go back to Richel Bilderbeek's C++ page.

Go back to Richel Bilderbeek's homepage.

(C++) stream

Global streams

stream (data) types

stream operations

Stream format flags

Stream flag field

Stream manipulators

stream code snippets