# *

(Redirected from Asterisk)

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*

## standard Pascal

The symbol `*`, pronounced “asterisk”, is used in Pascal to

• indicate multiplication of numbers, or
• form the intersection of sets.
```program asteriskDemo(input, output, stderr);

type
day = (monday, tuesday, wednesday,
thursday, friday, saturday, sunday);

var
i: longint;
n: real;
m: set of day;

begin
// multiplication operator
i := 6 * 7;      // i becomes 42
n := 6.0 * 7.0;  // n becomes 42.0

// intersection operator
m := [saturday, sunday] * [sunday, monday];
// m is now {sunday}
end.
```

## exponentiation

Furthermore, in FPC the exponentiation operator consisting of two consecutive asterisks `**` exists. However, it is only defined for variants by the standard system unit, which requires a variant manager being installed. In order to actually use it with integers, one can define it on their own:

```program exponentiation(input, output, stdErr);

{\$mode objFPC}

operator ** (const base: integer; const exponent: integer): integer;
begin
if base <> 0 then
begin
result := trunc(exp(ln(base) * exponent));
end;
end;

begin
writeLn(2 ** 10); // will print 1024
end.
```

For readily available overloads, the `math` and `matrix` unit can be included.

## other appearances

In Pascal's years of childhood computer systems did not necessarily knew the comment delimiting characters opening and closing curly brace `{ }`. To make block comments available on such systems an alternative syntax, the bigramms `(*` and `*)` are allowed, too, but they can't be interchanged willynilly: `(*` has to match a `*)`, and can not match a `}` even though it is closing a block comment, too.

Also, if C like operators were allowed by the compiler directive `{\$COperator on}`, the short syntax for `i := i * n` reads `i *= n`. But by doing so, you leave the domain of Pascal. Your code technically, mathematically speaking becomes wrong.

In ASCII, the character code decimal `42` (or hexadecimal `2A`) is defined to be `*`.

 single characters character pairs