Compound conditional in IF statement

[Flyzone]

Why won't this compile?

If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or
(SrcStrChar >= "a" and SrcStrChar <= "z")) then
ElemStr = ElemStr + SrcStrChar
Endif

I'm not interested in poor form feedback or alternative coding. I just want to know why this multi-line test won't compile. Somewhere I read a colon might be needed? SrcStrChar is 'Dim as String'.

[D.J.Peters]

You have to use the "_" char to concatenate the splitted code line.

Joshy

Code: Select all

dim as string SrcStrChar,ElemStr
If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or _
    (SrcStrChar >= "a" and SrcStrChar <= "z")) then
  ElemStr &= SrcStrChar
End if

or write it in one line:

Code: Select all

dim as string SrcStrChar,ElemStr
If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or (SrcStrChar >= "a" and SrcStrChar <= "z")) then
  ElemStr &= SrcStrChar
End if

[Munair]

In most BASIC languages there is no character to mark the end of a statement, like for example in Pascal that uses the semicolon:

Code: Select all

if a > b then a := b;

In BASIC (FreeBASIC is no different):

Code: Select all

if a > b then a = b

The line ending itself is considered the end of the statement. So to divide a single statement over more than one line the underscore character must be used, like D.J. Peters said:

Code: Select all

if a > b then _
  a = b

Admittedly, a closing statement character would be more comfortable, but this is just the way it is.

[Flyzone]

You have to use the "_" char to concatenate the splitted code line.

Joshy

Code: Select all

dim as string SrcStrChar,ElemStr
If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or _
    (SrcStrChar >= "a" and SrcStrChar <= "z")) then
  ElemStr &= SrcStrChar
End if

or write it in one line:

Code: Select all

dim as string SrcStrChar,ElemStr
If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or (SrcStrChar >= "a" and SrcStrChar <= "z")) then
  ElemStr &= SrcStrChar
End if

Thanks. Can't believe I didn't run across that in the doc. I thought I had originally coded it just as you showed in the 2nd example but it didn't work for me which is why I split it then got other errors. Both of these work for me now so I'm not sure what happened. I appreciate the help.

[Flyzone]

In most BASIC languages there is no character to mark the end of a statement, like for example in Pascal that uses the semicolon:

Code: Select all

if a > b then a := b;

In BASIC (FreeBASIC is no different):

Code: Select all

if a > b then a = b

The line ending itself is considered the end of the statement. So to divide a single statement over more than one line the underscore character must be used, like D.J. Peters said:

Code: Select all

if a > b then _
  a = b

Admittedly, a closing statement character would be more comfortable, but this is just the way it is.

Thanks. I don't particularly like that underscore but was unaware of it and it works for me now. I think the need for this is for what we used to refer to as "one pass compilers" that require these leading "tells".
Yes, I'd actually prefer a closing statement char -- tho the semi is pretty ugly :) How about a question mark or even a user-defined char since some of us are uncertain about our code to begin with!

[MrSwiss]

Yes, I'd actually prefer a closing statement char

Well, this is BASIC, which never had such a thing.
You'll have to use C or Pascal, if you're insisting on a closing statement.

How about a question mark or ...

No go, the question mark is a synonym for 'Print' statement, in FB.
See FB-Manual, for more detailed information ...

[grindstone]

IMHO it considerably eases the typing of the FB source code that there's no closing statement.

[Munair]

IMHO it considerably eases the typing of the FB source code that there's no closing statement.

Funny you say that. When I switch from a Pascal project to BASIC I often tend to explicitely 'close' each statement. When it's the other way around, I leave Pascal lines without. Who invented all those different programming languages ?!?!!

[Flyzone]

You have to use the "_" char to concatenate the splitted code line.

Joshy

Code: Select all

dim as string SrcStrChar,ElemStr
If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or _
    (SrcStrChar >= "a" and SrcStrChar <= "z")) then
  ElemStr &= SrcStrChar
End if

or write it in one line:

Code: Select all

dim as string SrcStrChar,ElemStr
If ((SrcStrChar >= "A" and SrcStrChar <= "Z") or (SrcStrChar >= "a" and SrcStrChar <= "z")) then
  ElemStr &= SrcStrChar
End if

Thanks. Can't believe I didn't run across that in the doc. I thought I had originally coded it just as you showed in the 2nd example but it didn't work for me which is why I split it then got other errors. Both of these work for me now so I'm not sure what happened. I appreciate the help.

Is the ampersand a typo in the statement?:
ElemStr &= SrcStrChar

[Josep Roca]

Is the ampersand a typo in the statement?:
ElemStr &= SrcStrChar

No, it is a valid operator.

[D.J.Peters]

I += 1 is the same as i = i + 1 add. two numbers
s &= "a" is the same as s = s & "a" is same as s = s + "a" concatenate two strings

Joshy

[sancho3]

s &= "a" is the same as s = s & "a" is same as s = s + "a" concatenate two strings

Except that & converts the right hand side to a string before concatenation.

Code: Select all

dim as integer max = 12
dim as string s = "moo"
'print s + max   	' can't do this
print s & max

[D.J.Peters]

Except that & converts the right hand side to a string before concatenation.

You are right I forgot it. :-)

Joshy