Description

"If..Else" constructs are used to perform as exclusive alternatives either one group of instructions or an alternate group of instructions. The syntax of an "If..Else" construct is:

If <conditional expression> then
  <statement>
else
  <statement>;

If the condition is true the statement following the "then" is performed. If the condition is not true the statement following the "else" is performed. For example:

If XAxis.ActualPosition > 2000 then
  XAxisBeyondLimit:=true
else
  XAxisBeyondLimit:=false;

A semicolon does not follow the statement preceding the "else". The entire construct, from the compiler's point of view, is one single statement. Semicolons do not come until the end of the statement. If an unnecessary semicolon is found before the "else" the compiler will indicate it should be removed.

If..Else statements can be nested to produce one-action-from-many type selections. For example:

if Today=Monday then
  Prompter.Writeln(‘What happened to the weekend?’)
else if Today=Tuesday then
  Prompter.Writeln(‘Where is the coffee?’)
else if Today=Wednesday then
  Prompter.Writeln(‘Half way there....’)
else if Today=Thursday then
  Prompter.Writeln(‘We are almost there...’)
else if Today=Friday then
  Prompter.Writeln(‘TGIF!’)
else
  Prompter.Writeln(‘It s the weekend!’);

The Last else handles all the cases that did not qualify in the proceeding tests. Note again, that the semicolon does not occur until after the last statement to conclude the entire group. The language does not have an explicit "Case" statement. This "If..Else" structure can accomplish the behavior of a case statement.