This UDT thing really bugs me...

[Pete]

You can use STATIC with UDTs, but unless I'm missing something, you can't pass a UDT as a single parameter. Instead, you have to do a DIM SHARED of the TYPE, or  pass each variable assigned to the UDT like page.x, page. y, page. z, etc. I don't see why you shouldn't be able to pass the type as a parameter. What are we, a Third World Language?

Pete

[johnno56]

Please excuse my ignorance... 'UDT'?

[STxAxTIC]

what?

Code: QB64: [Select]

1. OPTION _EXPLICIT
2.  
3. TYPE thing
4.     whatever AS INTEGER
5.     whateverelse AS DOUBLE
6. END TYPE
7.  
8. DIM dog AS thing
9.  
10. dog.whatever = 5
11. dog.whateverelse = 0.33
12.  
13. PRINT dosomething(dog)
14.  
15. END
16.  
17. FUNCTION dosomething (i AS thing)
18.     DIM a AS INTEGER
19.     DIM b AS DOUBLE
20.     a = i.whatever
21.     b = i.whateverelse
22.     dosomething = a + b
23. END FUNCTION

[bplus]

UDT stands for User Defined Type

Here is my what????

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. REDIM array(1 TO 20) AS UDT
6. FOR i = 1 TO 20
7.     array(i).x = i
8.     array(i).s = CHR$(64 + i)
9. NEXT
10. FOR i = 2 TO 20 STEP 2
11.     showArray array(), i
12. NEXT
13.  
14.  
15. SUB showArray (a() AS UDT, i)
16.     PRINT a(i).x, a(i).s
17. END SUB
18.  

[johnno56]

Thanks bplus.

[Pete]

UDT stands for User Defined Type

Here is my what????

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. REDIM array(1 TO 20) AS UDT
6. FOR i = 1 TO 20
7.     array(i).x = i
8.     array(i).s = CHR$(64 + i)
9. NEXT
10. FOR i = 2 TO 20 STEP 2
11.     showArray array(), i
12. NEXT
13.  
14.  
15. SUB showArray (a() AS UDT, i)
16.     PRINT a(i).x, a(i).s
17. END SUB
18.  

So passed as "a" it works...

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. DIM array AS UDT
6.  
7. array.x = 10
8. array.s = CHR$(65)
9.  
10. CALL showArray(array, i)
11.  
12. SUB showArray (a AS UDT, i)
13.     PRINT a.x, a.s
14. END SUB
15.  

and this works...

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. DIM array AS UDT
6.  
7. array.x = 10
8. array.s = CHR$(65i)
9.  
10. CALL showArray(array, i)
11.  
12. SUB showArray (array, i)
13.     PRINT array.x, array.s
14. END SUB
15.  

but if you don't use array as UDT in the SUB, it fails...

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. DIM array AS UDT
6.  
7. array.x = 10
8. array.s = CHR$(65)
9.  
10. CALL showArray(array, i)
11.  
12. SUB showArray (array, i)
13.     PRINT array.x, array.s
14. END SUB
15.  

My guess is the reason is something like you have to not only pass the variable, but when SHARED is not used, you have to pass the type to the sub, along with the variable. If that's the reason, maybe it should be noted that you couldn't write array = 10 in the code, either. That stated, what other reason(s), if any, would prevent QB64 from allowing the last example to compile and work?

Pete

[STxAxTIC]

what the hell is

Code: QB64: [Select]

1. CHR$(65i)

[FellippeHeitor]

If you don't write AS UDT, the array parameter is a SINGLE type variable.

[STxAxTIC]

Ah, came back to say what Fellippe just said ^.

Funny, cause all he did was copypaste my example but deleted too much :-)

[Pete]

what the hell is

Code: QB64: [Select]

1. CHR$(65i)

It's a TYPeO.

Pete

[Pete]

If you don't write AS UDT, the array parameter is a SINGLE type variable.

No it isn't, because it was DIMmed as a TYPE. That's why the IDE won't accept it as a variable.

[FellippeHeitor]

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. DIM array AS UDT
6.  
7. array.x = 10
8. array.s = CHR$(65)
9.  
10. CALL showArray(array, i)
11.  
12. SUB showArray (array AS UDT, i)
13.     PRINT array.x, array.s
14. END SUB
15.  
16.  

[FellippeHeitor]

'array' in the main module is a separate entity from 'array' as a parameter to a sub.

[Pete]

And that was my reasoning, too, but since QB64 won't allow "array" to be used as a variable, once it is assigned as a UDT, maybe it could be made to be passed as...

Code: QB64: [Select]

1. TYPE UDT
2.     x AS LONG
3.     s AS STRING
4. END TYPE
5. DIM array AS UDT
6.  
7. array.x = 10
8. array.s = CHR$(65)
9.  
10. CALL showArray(array, i)
11.  
12. SUB showArray (array, i)
13.     PRINT array.x, array.s
14. END SUB
15.  

What "bugs" me about having to add the "AS UDT" in the sub is the extra size it adds to the line of code, making it more difficult to read when there are several additional parameters passed.

My guess is as much as I would like my abbreviated example, it would conflict with too many established constructs such as...

Code: QB64: [Select]

1. DIM a AS INTEGER
2.  
3. CALL showArray(a)
4.  
5. SUB showArray (a)
6.     a = 1.5
7.     PRINT a
8. END SUB

vs...

Code: QB64: [Select]

1. DIM a AS INTEGER
2.  
3. CALL showArray(a)
4.  
5. SUB showArray (a AS INTEGER)
6.     a = 1.5
7.     PRINT a
8. END SUB

...for examples.

Well, as much as I have't worked with UDT's in the past, I may just bite the bullet on this one, and consider turning more of my variables into UDT's. That way, I can pass more variables under fewer parameters, and shorten those SUB () lines.

Thanks for batting this around with me.

Pete

[luke]

My guess is as much as I would like my abbreviated example, it would conflict with too many established constructs such as...

Code: QB64: [Select]

1. DIM a AS INTEGER
2.  
3. CALL showArray(a)
4.  
5. SUB showArray (a)
6.     a = 1.5
7.     PRINT a
8. END SUB

I find it amusing you refer to this as established usage, since this is QB64-only code. QB45 will complain about a type mismatch, because you're trying to pass an integer by-reference to a function expecting a single. QB64 is being "helpful" and implicitly adding a CINT() around your argument.

This may cause surprises if you expect the parameter to be an output parameter:

Code: QB64: [Select]

1. DIM p AS INTEGER
2. DIM q AS INTEGER
3. p = 2
4. q = 3
5. PRINT p, q
6. xchg p, q
7. PRINT p, q
8.  
9. SUB xchg (a, b)
10.     temp = a
11.     a = b
12.     b = temp
13. END SUB

Doesn't swap the values because they're being passed by-value (and yes, I know we already have a SWAP command).