The If .. then .. else.. prototype syntax is
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If then statements
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The expression between the if and then keywords must have a Boolean result type. If the expression evaluates to True then the statement following the then keyword is executed.
If the expression evaluates to False, then the statement following the else keyword is executed, if it is present.
Some points to note:
For example:
If exp1 Then If exp2 then Stat1 else stat2;
Despite its appearance, the statement is syntactically equivalent to
If exp1 Then begin If exp2 then Stat1 else stat2 end;
and not to
{ NOT EQUIVALENT } If exp1 Then begin If exp2 then Stat1 end else stat2;
If it is this latter construct which is needed, the begin and end keywords must be present. When in doubt, it is better to add them.
The following is a valid statement:
If Today in [Monday..Friday] then WriteLn ('Must work harder') else WriteLn ('Take a day off.');