Walter,

I can successfully use the switch/case construct to compare equality of a
string, but the same can't be said for using the "if" statement. For
example:
  if (a == "Hello") ...
doesn't succeed.
whereas:
  switch (a)
  {
    case "Hello": ...
  }
does work.

I'm also getting an error during compile ('array.length' is not an lvalue)
with the following:
  int[] array;

  array[array.length++] = 0;
  array[array.length++] = 1;
  array[array.length] = 2;

Gary.

"Gary" <gedumer@bcpl.net> wrote in message news:a7qll4$1870$1@digitaldaemon.com...

> I can successfully use the switch/case construct to compare equality of a
> string, but the same can't be said for using the "if" statement. For
> example:
>   if (a == "Hello") ...
> doesn't succeed.

Currently, you cannot use == and friends to compare strings, and arrays in general. You have to use cmp():

    if (!cmp(a, "Hello")) ...

Hopefully some operator to compare arrays will be added.


> I'm also getting an error during compile ('array.length' is not an lvalue)
> with the following:
>   int[] array;
>
>   array[array.length++] = 0;
>   array[array.length++] = 1;

This one (and array.length--) I was asking once, but no luck =)

Walter... Any comments?

Pavel Minayev <evilone@omen.ru> wrote in message news:a7qnim$19c9$1@digitaldaemon.com...
> "Gary" <gedumer@bcpl.net> wrote in message news:a7qll4$1870$1@digitaldaemon.com...
>
> > I can successfully use the switch/case construct to compare equality of
a
> > string, but the same can't be said for using the "if" statement. For
> > example:
> >   if (a == "Hello") ...
> > doesn't succeed.
>
> Currently, you cannot use == and friends to compare strings, and arrays in general. You have to use cmp():
>
>     if (!cmp(a, "Hello")) ...
>
> Hopefully some operator to compare arrays will be added.
>
>
> > I'm also getting an error during compile ('array.length' is not an
lvalue)
> > with the following:
> >   int[] array;
> >
> >   array[array.length++] = 0;
> >   array[array.length++] = 1;
>
> This one (and array.length--) I was asking once, but no luck =)
>
>

"Gary" <gedumer@bcpl.net> wrote in message news:a7qll4$1870$1@digitaldaemon.com...
> I'm also getting an error during compile ('array.length' is not an lvalue)
> with the following:
>   int[] array;
>
>   array[array.length++] = 0;
>   array[array.length++] = 1;
>   array[array.length] = 2;

I disabled setting array.length for operators other than assignment because it reallocates the array, which is an expensive operation. Adding array elements one by one, incrementing the array length each time, will have terrible runtime performance.

The way to do it is to preallocate your best guess as to what you'll need, stuff the array elements, and then do an assignment to set the final size. If, as you're stuffing array elements, you run out of length, doubling the existing array length is a good strategy.

Walter <walter@digitalmars.com> wrote in message news:a7r3am$1gcu$1@digitaldaemon.com...
>
> "Gary" <gedumer@bcpl.net> wrote in message news:a7qll4$1870$1@digitaldaemon.com...
> > I'm also getting an error during compile ('array.length' is not an
lvalue)
> > with the following:
> >   int[] array;
> >
> >   array[array.length++] = 0;
> >   array[array.length++] = 1;
> >   array[array.length] = 2;
>
> I disabled setting array.length for operators other than assignment
because
> it reallocates the array, which is an expensive operation. Adding array elements one by one, incrementing the array length each time, will have terrible runtime performance.
>
> The way to do it is to preallocate your best guess as to what you'll need, stuff the array elements, and then do an assignment to set the final size. If, as you're stuffing array elements, you run out of length, doubling the existing array length is a good strategy.
>
>
Exactly... how would you do that?

Also... when do you expect string comparison to be incorporated?

Walter <walter@digitalmars.com> wrote in message news:a7r3am$1gcu$1@digitaldaemon.com...
>
> "Gary" <gedumer@bcpl.net> wrote in message news:a7qll4$1870$1@digitaldaemon.com...
> > I'm also getting an error during compile ('array.length' is not an
lvalue)
> > with the following:
> >   int[] array;
> >
> >   array[array.length++] = 0;
> >   array[array.length++] = 1;
> >   array[array.length] = 2;
>
> I disabled setting array.length for operators other than assignment
because
> it reallocates the array, which is an expensive operation. Adding array elements one by one, incrementing the array length each time, will have terrible runtime performance.
>
> The way to do it is to preallocate your best guess as to what you'll need, stuff the array elements, and then do an assignment to set the final size. If, as you're stuffing array elements, you run out of length, doubling the existing array length is a good strategy.
>
>

"Gary" <gedumer@bcpl.net> wrote in message news:a7r5iq$1hg6$1@digitaldaemon.com...
> > The way to do it is to preallocate your best guess as to what you'll
need,
> > stuff the array elements, and then do an assignment to set the final
size.
> > If, as you're stuffing array elements, you run out of length, doubling
the
> > existing array length is a good strategy.
> Exactly... how would you do that?

array.length = 100;        // guess
for (i = 0; 1; i++)
{    c = getinput();
      if (!c)
        break;
      if (i == array.length)
        array.length = array.length * 2;
      array[i] = c;
}
array.length = i;

Picking a good initial guess is an art, but you usually can pick a value covering 99% of the cases. For example, suppose you are gathering user input from the console - it's unlikely to be longer than 80.

Walter <walter@digitalmars.com> wrote in message news:a7r7ok$1ing$1@digitaldaemon.com...
>
> "Gary" <gedumer@bcpl.net> wrote in message news:a7r5iq$1hg6$1@digitaldaemon.com...
> > > The way to do it is to preallocate your best guess as to what you'll
> need,
> > > stuff the array elements, and then do an assignment to set the final
> size.
> > > If, as you're stuffing array elements, you run out of length, doubling
> the
> > > existing array length is a good strategy.
> > Exactly... how would you do that?
>
> array.length = 100;        // guess
> for (i = 0; 1; i++)
> {    c = getinput();
>       if (!c)
>         break;
>       if (i == array.length)
>         array.length = array.length * 2;
>       array[i] = c;
> }
> array.length = i;
>
> Picking a good initial guess is an art, but you usually can pick a value covering 99% of the cases. For example, suppose you are gathering user
input
> from the console - it's unlikely to be longer than 80.
>
>
>

WOW!!! That's a far cry from the example in the docs... which is what I was trying to follow. I LIKE IT:)

Thanks... Gary.

"Gary" <gedumer@bcpl.net> wrote in message news:a7r8b3$1j12$1@digitaldaemon.com...
> WOW!!! That's a far cry from the example in the docs... which is what I
was
> trying to follow. I LIKE IT:)

Looks like I should amend the docs <g>.

"Walter" <walter@digitalmars.com> wrote in message news:a7r3am$1gcu$1@digitaldaemon.com...

> I disabled setting array.length for operators other than assignment
because
> it reallocates the array, which is an expensive operation. Adding array elements one by one, incrementing the array length each time, will have terrible runtime performance.

You're probably right... but what about -- and -=? They sound like a replacement for pop_back() of STL containers - a thing that is of common use. Currently, I have to use

    s.length = s.length - 1;

Why not

    s.length--;

?