Manual Reference Pages - lgt (3fortran)

NAME

LGT(3) - [CHARACTER:COMPARE] ASCII Lexical greater than

SYNOPSIS

result = lgt(string_a, string_b)

          elemental logical function lgt(string_a, string_b)

           character(len=*),intent(in) :: string_a
           character(len=*),intent(in) :: string_b

CHARACTERISTICS

o STRING_A is default character or an ASCII character.

o STRING_B is the same type and kind as STRING_A

o the result is a default logical

DESCRIPTION

LGT(3) determines whether one string is lexically greater than another string, where the two strings are interpreted as containing ASCII character codes. If the String A and String B are not the same length, the shorter is compared as if spaces were appended to it to form a value that has the same length as the longer.
In general, the lexical comparison intrinsics LGE, LGT, LLE, and LLT differ from the corresponding intrinsic operators .ge., .gt., .le., and [char46]lt., in that the latter use the processor’s character ordering (which is not ASCII on some targets), whereas the former always use the ASCII ordering.

OPTIONS

o STRING_A : string to be tested

o STRING_B : string to compare to STRING_A

RESULT

Returns .true. if string_a > string_b, and .false. otherwise, based on the ASCII ordering.
If both input arguments are null strings, .false. is returned.
If either string contains a character not in the ASCII character set, the result is processor dependent.

EXAMPLES

Sample program:

    program demo_lgt
    implicit none
    integer :: i
       print *,’the ASCII collating sequence for printable characters’
       write(*,’(1x,19a)’)(char(i),i=32,126)

       write(*,*) lgt(’abc’,’ABC’)          ! [T] lowercase is > uppercase
       write(*,*) lgt(’abc’,’abc  ’)        ! [F] trailing spaces

       ! If both strings are of zero length the result is false.
       write(*,*) lgt(’’,’’)                ! [F]
       write(*,*) lgt(’’,’a’)               ! [F] the null string is padded
       write(*,*) lgt(’a’,’’)               ! [T]
       write(*,*) lgt(’abc’,[’abc’,’123’])  ! [F T]  scalar and array
       write(*,*) lgt([’cba’, ’123’],’abc’) ! [T F]
       write(*,*) lgt([’abc’,’123’],[’cba’,’123’]) ! [F F]  both arrays
    end program demo_lgt

Results:

     >  the ASCII collating sequence for printable characters
     >   !"#$%&’()*+,-./012
     >  3456789:;<=>?@ABCDE
     >  FGHIJKLMNOPQRSTUVWX
     >  YZ[\]^_‘abcdefghijk
     >  lmnopqrstuvwxyz{|}~
     >  T
     >  F
     >  F
     >  F
     >  T
     >  F T
     >  T F
     >  F F

STANDARD

FORTRAN 77

o	STRING_A is default character or an ASCII character.
o	STRING_B is the same type and kind as STRING_A
o	the result is a default logical

o	STRING_A : string to be tested
o	STRING_B : string to compare to STRING_A

Manual Reference Pages - lgt (3fortran)

NAME

SYNOPSIS

CHARACTERISTICS

DESCRIPTION

OPTIONS

RESULT

EXAMPLES

STANDARD

SEE ALSO