Cross Ref > Statements

Use a try..except..end block to trap and process errors.

Delphi also offers a try...finally where code will execute in the finally section no matter what. It's common to put a try..except inside a try..finally.

var
  y : Double;
begin
  try
    y := 0;
    y := (1/y);
    ShowMessage(FloatToStr(y));
  except
    ShowMessage('You cannot divide by zero.');
  end;
end;

ObjectPAL has a try...onFail statement but does not have a finally-type component. However, the code afer endTry will execute.

try

onFail

endTry

var
  i SmallInt
endVar

try
  i = 0
  i = 1/i
onFail
  msgInfo("", "You cannot divide by zero.")
endTry

 Debugging ObjectPAL Code

Notice in the more complete example that the semicolon for the begin..end block after end is not included. That tells the compiler something else is coming (the statement is not finished). Also note the semicolon is missing right before the final "else" statement.

Note: The following example uses floating point literals. In Delphi, to specify a fractional floating point literal between 1 and -1, you preceed the decimal with a 0; otherwise, you will get a compiler error (i.e. .1 + .1 does not work).

if (0.1 + 0.1 + 0.1) = 0.3 then
  ShowMessage('Correct')
else
  ShowMessage('Not correct');

//Complete example:
if x = true then
begin 

  ShowMessage('x is true');

end

Else If y = 'Mike' Then 

  ShowMessage('hello mike')

Else 

  ShowMessage('last option');

 Delphi If Statement (If..Else If..Else)

ObjectPAL supports a simple If...Else...EndIf statement.

Notice ObjectPAL does not support an ElseIf feature as part of an if statement. Instead use a switch statement

Syntax Example:   'Does ObjectPAL evaluate the math correctly? No! If (.1 + .1 + .1) = .3 Then   msgInfo("", "Correct") Else   msgInfo("", "Not correct") EndIf 'Switch statement example. switch case x = "Nate": MsgInfo("", "Hi Nate") case x = "Felicia": MsgInfo("", "Hi Felly") otherwise: MsgInfo("", "Who are you?") endSwitch