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

.. _abs:

.. index:: ABS

.. index:: CABS

.. index:: DABS

.. index:: IABS

.. index:: ZABS

.. index:: CDABS

.. index:: BABS

.. index:: IIABS

.. index:: JIABS

.. index:: KIABS

.. index:: absolute value

ABS --- Absolute value
**********************

.. function:: ABS(A)

  ``ABS(A)`` computes the absolute value of ``A``.

  :param A:
    The type of the argument shall be an ``INTEGER``,
    ``REAL``, or ``COMPLEX``.

  :return:
    The return value is of the same type and
    kind as the argument except the return value is ``REAL`` for a
    ``COMPLEX`` argument.

  Standard:
    Fortran 77 and later, has overloads that are GNU extensions

  Class:
    Elemental function

  Syntax:
    .. code-block:: fortran

      RESULT = ABS(A)

  Example:
    .. code-block:: fortran

      program test_abs
        integer :: i = -1
        real :: x = -1.e0
        complex :: z = (-1.e0,0.e0)
        i = abs(i)
        x = abs(x)
        x = abs(z)
      end program test_abs

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

       * - Name
         - Argument
         - Return type
         - Standard

       * - ``ABS(A)``
         - ``REAL(4) A``
         - ``REAL(4)``
         - Fortran 77 and later
       * - ``CABS(A)``
         - ``COMPLEX(4) A``
         - ``REAL(4)``
         - Fortran 77 and later
       * - ``DABS(A)``
         - ``REAL(8) A``
         - ``REAL(8)``
         - Fortran 77 and later
       * - ``IABS(A)``
         - ``INTEGER(4) A``
         - ``INTEGER(4)``
         - Fortran 77 and later
       * - ``BABS(A)``
         - ``INTEGER(1) A``
         - ``INTEGER(1)``
         - GNU extension
       * - ``IIABS(A)``
         - ``INTEGER(2) A``
         - ``INTEGER(2)``
         - GNU extension
       * - ``JIABS(A)``
         - ``INTEGER(4) A``
         - ``INTEGER(4)``
         - GNU extension
       * - ``KIABS(A)``
         - ``INTEGER(8) A``
         - ``INTEGER(8)``
         - GNU extension
       * - ``ZABS(A)``
         - ``COMPLEX(8) A``
         - ``REAL(8)``
         - GNU extension
       * - ``CDABS(A)``
         - ``COMPLEX(8) A``
         - ``REAL(8)``
         - GNU extension