If Else If Else - How Can It Work in Delphi? [Closed]

Question

How does this piece of code work?

 if name <> '' then 

    begin 
      sql_1
    end

else if PARAMETRIC then 
    begin
         sql2
    end 
else 
    begin
        sql3
   end
 end;

execute sql choosed by if or elseif or else.....

name = is a string
PARAMETRIC = is a boolean
sql1, sql2, sql3 are different queries (sorry for forgot it :( )

Accepted Answer

In short:

If name is not empty, only sql_1 will be executed
If name is empty and PARAMETRIC is true, only sql_2 will be executed
If name is empty and PARAMETRIC is false, only sql_3 will be executed

You can always add begin/end statements to make it look more obvious.

if name <> '' then 
    begin 
      sql_1
    end
else 
    begin
        if PARAMETRIC then 
            begin
                sql2
            end 
        else 
            begin
                sql3
            end;
    end;
end;

Answer 2

You say (in comments) you know C#. Well, in Delphi it works exactly the same. You can write if .. else statements, and add an extra condition after the else.

In Delphi:

if condition1 then
begin // Open multi-line statement.
  Do1a;
  Do1b;
end
else if condition2 then
  Do2;

In C#:

if (condition1)
{ // Open multi-line statement.
  Do1a;
  Do1b;
}
else if (condition2)
  Do2;

So, while I don't really understand the confusion, the answer to your question is: No, they don't get all executed. If condition1 is true, the 'elses' won't be executed. If condition1 is false and condition2 is true, the second statement (do2) is executed. If both are false, nothing is executed (or in your case, the conditionless else is executed, so you get SQL3).

If Else If Else - How Can It Work in Delphi? [Closed]

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Sophia Al-Mansoor