gcc/fortran/doc/gfortran/intrinsic-procedures/real.rst

..
  Copyright 1988-2022 Free Software Foundation, Inc.
  This is part of the GCC manual.
  For copying conditions, see the copyright.rst file.

.. _real:

.. index:: REAL

.. index:: REALPART

.. index:: FLOAT

.. index:: DFLOAT

.. index:: FLOATI

.. index:: FLOATJ

.. index:: FLOATK

.. index:: SNGL

.. index:: conversion, to real

.. index:: complex numbers, real part

REAL --- Convert to real type
******************************

.. function:: REAL(A [, KIND])

  ``REAL(A [, KIND])`` converts its argument :samp:`{A}` to a real type.  The
  ``REALPART`` function is provided for compatibility with :command:`g77`,
  and its use is strongly discouraged.

  :param A:
    Shall be ``INTEGER``, ``REAL``, or
    ``COMPLEX``.

  :param KIND:
    (Optional) An ``INTEGER`` initialization
    expression indicating the kind parameter of the result.

  :return:
    These functions return a ``REAL`` variable or array under
    the following rules:

  Standard:
    Fortran 77 and later, with :samp:`{KIND}` argument Fortran 90 and later, has GNU extensions

  Class:
    Elemental function

  Syntax:
    .. code-block:: fortran

      RESULT = REAL(A [, KIND])
      RESULT = REALPART(Z)

  Example:
    .. code-block:: fortran

      program test_real
        complex :: x = (1.0, 2.0)
        print *, real(x), real(x,8), realpart(x)
      end program test_real

  Specific names:
    .. list-table::
       :header-rows: 1

       * - Name
         - Argument
         - Return type
         - Standard

       * - ``FLOAT(A)``
         - ``INTEGER(4)``
         - ``REAL(4)``
         - Fortran 77 and later
       * - ``DFLOAT(A)``
         - ``INTEGER(4)``
         - ``REAL(8)``
         - GNU extension
       * - ``FLOATI(A)``
         - ``INTEGER(2)``
         - ``REAL(4)``
         - GNU extension (-fdec)
       * - ``FLOATJ(A)``
         - ``INTEGER(4)``
         - ``REAL(4)``
         - GNU extension (-fdec)
       * - ``FLOATK(A)``
         - ``INTEGER(8)``
         - ``REAL(4)``
         - GNU extension (-fdec)
       * - ``SNGL(A)``
         - ``REAL(8)``
         - ``REAL(4)``
         - Fortran 77 and later

  See also:
    :ref:`DBLE`