ios_base& showbase ( ios_base& str );

<ios>

Show numerical base prefixes

Sets the showbase format flag for the str stream.

When the showbase format flag is set, numerical values are prefixed with their C++ base format prefix when insterted into the stream. These prefixes are, 0x for hexadecimal values, 0 for octal values and no prefix for decimal-base values.

This option can be unset with the noshowbase manipulator, inserting all numerical values without base format prefixes.

The showbase flag is not set in standard streams on initialization.

Parameters

str

Stream object where to apply.
Because this function is a manipulator, it is designed to be used alone with no arguments in conjunction with the insertion (<<) and extraction (>>) operations on streams (see example below).

Return Value

Example

// modify showbase flag
#include <iostream>
using namespace std;

int main () {
  int n;
  n=20;
  cout << hex << showbase << n << endl;
  cout << hex << noshowbase << n << endl;
  return 0;
}

The execution of this example displays something similar to:

0x14
14

See also