Newbie question about string declarations

[Hedley Moses]

Hi

PB newbie question. I'm trying to understand the difference between these two options for string declarations in PB. The manual does not seem to differentiate between then clearly. Are they essentially the same thing.

DIM a$
DIM a as STRING

Would appreciate if anyone shed some light please

Thanks

[Kev Peel]

They are the same. It's a throwback to the original BASIC syntax, which is why there are no type specifiers for ASCIIZ or VARIANTs (amongst others). Once you have declared the variable, the type specifier is optional.

I prefer the latter.

[Mike Doty]

Yes, they are the same.
When passing a value and using #DIM ALL (which you should always use)
the "a AS STRING" must be used instead of "a$" or each occurrance of
"a" must be defned as "a$" within the SUB or FUNCTION.
Personally, I use DIM a AS STRING unless in a hurry. Same answer as Kev.

#DIM ALL
FUNCTION PBMAIN () AS LONG
     test("abc")
END FUNCTION
SUB test(a$)
  ? a
END SUB
SUB test2(a AS STRING)
  ? a
END SUB

[Mel Bishop]

FYI: It's the same way with numbers.

dim a as long
a = 14

will compile as will:

a! = 14 (without the dim statement)

That is, of course, you need to not use the #DIM ALL compiler directive.

[Mike Doty]

You might consider using LOCAL instead of DIM.

#DIM ALL
GLOBAL gs AS STRING
FUNCTION PBMAIN () AS LONG
  gs = "abc"
  test
  ? "The value of gs> " + gs
  WAITKEY$
END FUNCTION
SUB Test
  LOCAL gs AS STRING  'assure value is local  scope
  'DIM   gs as STRING  'value takes the global scope
  gs = "def"
  ? "The value of gs> " + gs
END SUB

[Neil Croft]

FYI: It's the same way with numbers.

dim a as long
a = 14

will compile as will:

a! = 14 (without the dim statement)

That is, of course, you need to not use the #DIM ALL compiler directive.

Not quite. It will compile as a& = 14. Bang is a single.

[Cliff Nichols]

Technically "Dim" is for arrays, "Local" is for variables, although "Dim" compiles just as well for a variable (But its a bad habit I am trying to break myself )

Local MyString as String
Local MyLong as Long
Dim MyArrayString(0) as String
Dim MyArrayLong(0) as Long

[Mel Bishop]

..."Dim" is for arrays, "Local" is for variables...

Why?

global a() as string
-and-
dim a() as global string
-and-
global t as long
-and-
dim t as global long

Perform the same function so why is one "correct" and the other isn't? Both syntax styles are completely interchangeable.

To my way of thinking, it's all a matter of preference and going with whatever floats your boat.

If it ain't broke, don't fix it.

[Fred Buffington]

Neil, I don't believe that Mel was implying that
dim a as long
a=14

and
a!=14

were equivalent statements but rather to show that the numeric type
identifier could be used or declared and both are valid.

[Neil Croft]

Maybe so but that not what it said and it nearly gave me a heart attack as I know Longs are much faster than other data types and I have a lot of software running here that I suddenly thought was badly wrong.

[Michael Mattias]

Technically "Dim" is for arrays, "Local" is for variables, although "Dim" compiles just as well for a variable (But its a bad habit I am trying to break myself

DIM for scalar variables is a compiler-directing statement only (no executable code generated) .

DIM for arrays is both compiler-directing and executable, except when it is ignored completely (this is documented BTW).

Because of its schizophrenic behavior, DIM is not fun to work with. It is, however, a source of a 'warm and fuzzy' feeling because it is familiar.

Your mileage may vary.

[Michael Mattias]

My bad... amend that.....

" It is, however, for some a source of a 'warm and fuzzy' feeling ..."

[Hedley Moses]

Thanks folks that clears it up nicely

[Fred Buffington]

**deleted**