ios_base& showpoint ( ios_base& str );

<ios>

Show decimal point

Sets the showpoint format flag for the str stream.

When the showpoint format flag is set, the decimal point is always written for floating point values insterted into the stream, even for whole numbers. Following the decimal point, as many digits as necessary are written to match the precision internal setting for the stream (if any).

This flag can be unset with the noshowpoint manipulator. When the showpoint format flag is not set, the decimal point is only written for non-whole numbers.

The precision setting can be modified using the precision() member function of the stream.

The showpoint 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 showpoint flag
#include <iostream>
using namespace std;

int main () {
  double a, b, pi;
  a=30.0;
  b=10000.0;
  pi=3.1416;
  cout.precision (5);
  cout <<   showpoint << a << '\t' << b << '\t' << pi << endl;
  cout << noshowpoint << a << '\t' << b << '\t' << pi << endl;
  return 0;
}

The execution of this example displays something similar to:

30.000  10000.  3.1416
30      10000   3.1416

See also