Hi I've done these lines of code on freepascal:
type bigNum=string;
function bigMod(a:bigNum;b:longint):longint;
var i,hold:longint;
begin
hold:=0;
for i:=1 to length(a) do
hold:=(ord(a[i])-48+hold*10)mod b;
bigMod:=hold;
end;
uses sysutils;
var a,i,n:longint;
begin
readln(n);
a:=1;
for i:=1 to n-2 do
a:=a*2;
IntToStr(a);
writeln(bigMod(bigMod(a,n),1000000000));
end.
but when I run it, it said 'BEGIN' expected but 'USES' found,
what should I do to fix it? if i change 'BEGIN' on top of 'USES' its will be another error
The uses clause must appear after the (optional) program statement, but before any other statement. Move the uses clause to the top of the code, immediately after the program statement if indeed you have one.
Related
I am a beginner and using pascal and i am trying this problem that i attach. What should i do next? I am trying to make this program work by showing the "ayam" Function. But i don't know how to code the rest.
function ayam(a, b:integer) :
integer;
var
m: integer;
begin
readln(a) ;
readln(b) ;
readln(m) ;
begin
if (b=0) then
ayam:= 1 else
ayam:= a * ayam(a, b-1) mod m;
end;
writeln(ayam);
end;
The first thing I should say is that when a question is to do with coursework, as is obviously the case here, there is an unwritten convention that we do not write an answer which simply does your programming task for you. So in the following, I have not commented on whether the code inside your ayam function actually correctly implements what is required - that is for you to do.
Secondly, you did not say which Pascal implementation you are using. I have written the code of this answer in Lazarus, the IDE for FreePascal (aka FPC), which is the best of the freeware Pascal implementations currently available.
The first thing to do with your code is to re-format it the way it should be formatted,
using indentation of statements to reflect the structure of the steps you are
trying to code. Basically, your eye should be able to follow the code structure
as easily as possible. This gives something like this:
function ayam(a, b:integer) : integer;
var
m: integer;
begin
readln(a) ;
readln(b) ;
readln(m) ;
begin
if (b=0) then
ayam:= 1
else
ayam:= a * ayam(a, b-1) mod m;
end;
writeln(ayam);
end;
With that change made, it is pretty obvious that there is something wrong with
the logic of your code, because a and b are declared as input variables to
the ayam function but your code actually reads in their values via the
readln statements inside the function. This is what made me think that you think
you have done all that's necessary to write your program. In fact, you have not. What you are missing
is some code which sets up the input parameters a and b (and m, see below) in some way and then
invokes your ayam function to calculate its value and then does something with
the result. At the moment, your code simply defines ayam but takes no steps
to use it. So, to get your ayam function to do anything, you need to write a complete
Pascal program that uses it. Something like this:
program ayamprogram;
{ the following declares some variables for the program to use }
var
varA,
varB,
varM,
varResult : Integer;
{ next, we define the ayam function }
function ayam(a, b, m:integer) : integer;
begin
begin
if (b=0) then
ayam:= 1
else
ayam:= a * ayam(a, b-1, m) mod m;
end;
end;
{ now we write the code of the program, which reads in the values to be
used by ayam, then invokes ("calls") ayam to calculate its value and
assign its value to the varResult variable and then outputs the calculated
result using the writeln statement
}
begin
{ this is the code of the program }
readln(varA);
readln(varB);
readln(varM);
varResult := ayam(varA, varB, varM);
writeln('function ayam evaluates to ', varResult);
readln; { this causes the program to pause so you can see the result of the writeln statement }
end. { end of program }
Note that I have used different variable names for the variables which are supplied to ayam, varA, varB, varM, from the variable names used inside ayam to avoid confusion between them.
Note also that as it is bad practice to read user input inside an executing function, the value to be used for M is read in before ayam is called and is supplied to ayam as a third parameter.
A point you need to consider regarding the expression
ayam:= a * ayam(a, b-1, m) mod m
is whether the mod m should operate on the value of ayam(a, b-1, m) or on the entire expression including the a * as well; if so, parentheses can enforce the evaluation order you need, by writing
ayam:= (a * ayam(a, b-1, m)) mod m
I'm using xampp with phpMyAdmin to manage a MySql database.
When creating a function I got a "No Return Found" error, so I stripped down the function to narrow the origin of the error I got to the simplest case where it still doesn't work.
And the error message is this:
Apparently if the RETURN statement isn't the only thing on the code I get an error.
Assuming the actual code being executed against MySQL is:
CREATE FUNCTION `Contagem`() RETURNS INT(11)
SET #c = 0;
RETURN #c;
This will fail, because you have not wrapped the function in BEGIN...END.
Try instead to write this as your function declaration:
BEGIN
SET #c = 0;
RETURN #c;
END;
Alternatively, declare the function yourself directly in MySQL:
DELIMITER $$
CREATE FUNCTION `Contagem`() RETURNS INT(11)
BEGIN
SET #c = 0;
RETURN #c;
END $$
DELIMITER ;
When reviewing this post I was reading more carefully the error message I realized the MySql code to define the function didn't have BEGIN and END in it.
I assumed when typing function code with several lines that phpMyAdmin would know how to handle it, since the code text box has support to multiple lines of code.
So, putting BEGIN at the beginning and END at the end of the code solved my problem.
I'm new with PL/SQL I have a assignment where I need to make a function. The assignment is as follows:
> "Create a function 'afdeling_van:'
> - this function accepts a medewerkernummer(employee number) as argument
> - give the afdelingnummer(department number) from the medewerkernummer(employee number) back"
So I need to create a function with a parameter that returns a number. After that I probably need to add some code to make it return a medewerker(employee) number back.
I got pretty stuck with this one as I am really new to PL/SQL. What I do have at the moment is this:
declare
procedure afdeling_van(p_persoon in medewerkers.mnr%type)--table name with column name
is
begin
select med.mnr
from medewerkers med;
where mnr = p_persoon;
end afdeling_van;
begin
afdeling_van(10);
end;
It's not working for me. I have tried different solutions. But as I lack experience and I cannot find the solution or information that I need on the web. I am trying it to ask here
one other thing. I think it's similair to my problem. In the previous assignment I made a procedure instead of a function. The procedure is as follows:
declare
v_medewerker varchar2(50) := ontsla_med();
procedure ontsla_med(p_medewerkers in medewerkers.naam%type)
is
begin
delete from medewerkers
where naam = p_medewerkers;
end ontsla_med;
begin
ontsla_med('');
dbms_output.put_line('Medewerker: ' || v_medewerker || 'verwijdert uit medewerker, inschrijven en uitvoeringen bestand.' );
exception
when no_data_found then
dbms_output.put_line('Medewerker bestaat niet/ is al verwijderd.');
end;
/
this works except for the last dbms_output.put_line. If I remove the output line, then it will work and with the output line, it won't.
I hope my question is not too vague.
Thanks in advance.
You need to create a function instead of a procedure, and you've got a semi-colon in the wrong place. Try something like:
declare
nReturned_value MEDEWERKERS.AFDELINGNUMMER%TYPE;
FUNCTION afdeling_van(p_persoon in medewerkers.mnr%type) --table name with column name
RETURN MEDEWERKERS.AFDELINGNUMMER%TYPE
is
nAFDELINGNUMMER MEDEWERKERS.AFDELINGNUMMER%TYPE;
begin
select med.AFDELINGNUMMER
INTO nAFDELINGNUMMER
from medewerkers med
where mnr = p_persoon;
RETURN nAFDELINGNUMMER ;
end afdeling_van;
begin
nReturned_value := afdeling_van(10);
DBMS_OUTPUT.PUT_LINE('nReturned_value = ' || nReturned_value);
end;
Edit
In your second example, I don't believe that the line v_medewerker varchar2(50) := ontsla_med(); will compile. ontsla_med is a procedure rather than a function, and because procedures don't return anything they can't be used in an assignment statement.
However, v_medewerker is only used in the DBMS_OUTPUT line which you say causes a problem - thus, it may be that the compiler is eliminating the variable because it's not used if the DBMS_OUTPUT line is removed, thus eliminating the problem. Try changing the declaration to v_medwerker varchar2(50) := 'Hello'; and see if that helps.
I am making a MySQLand getting an error I dont know how to fix it. What the function should be doing is asking the user for input, this input should be stored in the corresponding variables and return a variable. But when i try run the function I am getting errors on the lines that store the variables. I am quite new to mySQL so i might be doing something stupid. Any help will be great thank you
This is is the mysql function
create or replace FUNCTION AD_AGENCY_INFO(agency_id in agency_id%type)
RETURN agency_id
DECLARE
v_no_of_runs AD_AGENCY.NO_OF_AD_RUNS%TYPE = '&enter_number_of_Runs';
v_credit_worthy AD_AGENCY.CREDIT_WORTHY%TYPE = '&enter_credit_worthy';
v_available_slots AD_AGENCY.AVAILABLE_SLOTS%TYPE = '&enter_available_slots';
v_status AD_AGENCY.STATUS%TYPE = '&enter_status';
BEGIN
insert into ad_agency values (agency_id, v_no_of_runs, v_credit_worthy,v_available_slots, v_status);
insert into ad (agency_id) values (agency_id);
commit;
RETURN (agency_id));
END AD_AGENCY_INFO;
The error that i am getting is the following and is the same for lines 7,8,9
Error(6,45): PLS-00103: Encountered the symbol "=" when expecting one of the following: := ( ; not null range default character The symbol ":= was inserted before "=" to continue.
Try changing your declare statement(s) to be
v_no_of_runs AD_AGENCY.NO_OF_AD_RUNS%TYPE := '&enter_number_of_Runs'
I'm writing long digit arythmetics. This is a function for adding to longint long binary digits. I need to output the sum inside the function, to debug it. How could I do it, without creating new variables?
function add(var s1,s2:bindata;shift:longint):bindata;
var l,i:longint;
o:boolean;
begin
writeln(s1.len,' - ',s2.len);
o:=false;
l:=max(s1.len,s2.len);
add.len:=0;
for i:=1 to l do begin
if o then Begin
if s1.data[i+shift] then Begin
if (s2.data[i]) then add.data[i+shift]:=true
Else add.data[i+shift]:=false;
End
else if s2.data[i] then add.data[i+shift]:=false
else Begin
add.data[i+shift]:=true;
o:=false;
End;
End
Else Begin
if s1.data[i+shift] then Begin
if s2.data[i] then
Begin
add.data[i+shift]:=false;
o:=true;
End
Else add.data[i+shift]:=true;
End
else if s2.data[i] then add.data[i+shift]:=true
else add.data[i+shift]:=false;
End;
output(add); //Can I output a variable?
end;
add.len:=l;
if o then Begin
inc(add.len);
add.data[add.len]:=true;
End;
end;
You are accumulating the result of the function within the function result variable, which is generally fine, but uses an outdated style, and leads to exactly the problem you're facing here. You're trying to report an intermediate value of the function result, and to do that, you're trying to reference the name of the function, add. When you do that, though, the compiler interprets it as an attempt to report the function itself, rather than the expected return value of this particular invocation of the function. You'll get the address of the function, if output is defined to accept function addresses; otherwise, you'll get a compiler error.
If your compiler offers a certain common language extension, then you should use the implicit Result variable to refer to the intermediate return value instead of continuing to refer to it by the function name. Since Result is declared implicitly, you wouldn't have to create any other variables. The compiler automatically recognizes Result and uses it as an alias for the function's return value. Simply find every place you write add within the function and replace it with Result. For example:
if o then begin
Inc(Result.len);
Result.data[Result.len] := True;
end;
Turbo Pascal, Free Pascal, GNU Pascal, and Delphi all support the implicit Result variable, but if you've managed to get stuck with a compiler that doesn't offer that extension, then you have no choice but to declare another variable. You could name it Result, and then implement your function with one additional line at the end, like so:
function add(var s1, s2: bindata; shift: longint): bindata;
var
l, i: longint;
o: boolean;
Result: bindata;
begin
{
Previous function body goes here, but with
`add` replaced by `Result`
}
{ Finally, append this line to copy Result into the
function's return value immediately before returning. }
add := Result;
end;