for i := 1 to n do with step 2 ?

[neuling]

Hi good afternoon.

how can you do the for with step 2 please?

Thanks.
greeting

[Kylev]

For i=1 to n step 2 in BASIC. Were you looking for a PASCAL version?

[TGB1718]

Pascal doesn't have a STEP, what you have to do is increment the counter inside the loop yourself

something like

 

for i := 1 to 10 do

  begin

     Writeln(i); {print i value}

      i := i+2;    { step 2 }

   end

 

[Rybags]

It'd be just +1 wouldn't it?

 

The end of the loop should increment by 1 regardless of what you do to the counter inside the loop.

[TGB1718]

11 hours ago, Rybags said:

It'd be just +1 wouldn't it?

Good spot  obviously the loop does the other increment, it was late last night 🙃

 

Probably in this case, a while-do loop would be more appropriate

 

var
    i: integer;
begin
i := 0;
while i < 10 do
begin
    Writeln(i);
    i := i+2;
end;

 

this will run the loop 5 times, output will be

0

2

4

6

8

 

 

 

Edited March 31 by TGB1718

[drunkeneye]

19 hours ago, TGB1718 said:

Pascal doesn't have a STEP, what you have to do is increment the counter inside the loop yourself

something like

 

for i := 1 to 10 do

  begin

     Writeln(i); {print i value}

      i := i+2;    { step 2 }

   end

 

 

just as a 'reminder', at least back in turbo pascal 6.0 it was not always

the case that var i will be really checked against. in x86 assembler it could

happen that pascal converts it something like 'mov ax, i; ... dec ax; loop ..'.

when this happens, you can change i all you want inside the loop without any

effect. whether this was used might depend on the optimization flags of

the compiler. or maybe also on the version of pascal. i have no clue if mad

pascal is 'affected'.

 

 

[neuling]

Hello, thanks for the help
greeting

15 hours ago, drunkeneye said:

 

just as a 'reminder', at least back in turbo pascal 6.0 it was not always

the case that var i will be really checked against. in x86 assembler it could

happen that pascal converts it something like 'mov ax, i; ... dec ax; loop ..'.

when this happens, you can change i all you want inside the loop without any

effect. whether this was used might depend on the optimization flags of

the compiler. or maybe also on the version of pascal. i have no clue if mad

pascal is 'affected'.

 

 

 

[neuling]

Hello, thanks for the help
greeting

[TGB1718]

17 hours ago, drunkeneye said:

just as a 'reminder', at least back in turbo pascal 6.0 it was not always

the case that var i will be really checked against.

Thanks for the info, btw. I've never used Pascal, but am aware of some of it's syntax

 

[tebe]

On 3/30/2024 at 9:28 PM, TGB1718 said:

Pascal doesn't have a STEP, what you have to do is increment the counter inside the loop yourself

something like

 

for i := 1 to 10 do

  begin

     Writeln(i); {print i value}

      i := i+2;    { step 2 }

   end

 

https://www.freepascal.org/docs-html/ref/refsu58.html#x168-19200013.2.4

 

• It is not allowed to change (i. e. assign a value to) the value of a loop variable inside the loop.

[neuling]

hello thanks for help.

 

greeting.