BTEST — Bit test function#

BTEST(I, POS)#

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

Parameters:

  • I – The type shall be INTEGER.

  • POS – The type shall be INTEGER.

Returns:

The return value is of type LOGICAL

Standard:

Fortran 90 and later, has overloads that are GNU extensions

Class:

Elemental function

Syntax:
RESULT = BTEST(I, POS)
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