Floating-point precision

• The value is represented with exact fraction part as specified by the precision.

• In default notation the precision specifies max number of meaningful digits to display before and after the decimal point.

• Precision can be changed by precision member function of the stream:

  #include <iostream>
  void main()
  {
      const double PI = 3.1415926;
      std::cout.precision( 7 );
      std::cout << PI << '\n';
  }
  /*
  Output: 3.141593
  */