9.51 BTEST — Bit test function

Description:

BTEST(I,POS) returns logical .TRUE. if the bit at POS in I is set. The counting of the bits starts at 0.

Standard:

Fortran 90 and later, has overloads that are GNU extensions

Class:

Elemental function

Syntax:

RESULT = BTEST(I, POS)

Arguments:
I The type shall be INTEGER.
POS The type shall be INTEGER.
Return value:

The return value is of type LOGICAL

Example:
program test_btest
    integer :: i = 32768 + 1024 + 64
    integer :: pos
    logical :: bool
    do pos=0,16
        bool = btest(i, pos) 
        print *, pos, bool
    end do
end program test_btest
Specific names:
Name Argument Return type Standard
BTEST(I,POS) INTEGER I,POS LOGICAL Fortran 95 and later
BBTEST(I,POS) INTEGER(1) I,POS LOGICAL(1) GNU extension
BITEST(I,POS) INTEGER(2) I,POS LOGICAL(2) GNU extension
BJTEST(I,POS) INTEGER(4) I,POS LOGICAL(4) GNU extension
BKTEST(I,POS) INTEGER(8) I,POS LOGICAL(8) GNU extension

© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gfortran/BTEST.html