PDF-Version - am Institut für Baustatik

= 2;
b = 2
In the first case we are assigning the value 2 to the variable a (Zuordnung). In the second case, we
are making the assertion that b is in fact already equal to 2 (Gleichung).
11.2.5 Quotes, Names, and Values (Anführungszeichen, Namen und Werte)
There are three types of quotes used in Maple: double-quotes ("); backquotes (`); and apostrophes or
single quotes (').
Double quotes are used to construct strings (Zeichenfolgen), as in:
> a := "This is a string";
a := This is a string
> a;
This is a string
Single quotes are used to delay evaluation (verzögerte Ausführung), as in:
> a := 1; x := 'a' + b;
a := 1
x := a + b
Backquotes are used to form symbols or names (Definition von Symbolen und Namen):
> `This is a name!` := 1;
This is a name! := 1
In the previous section, a mathematical variable was also described as an unassigned variable
(Platzhalter). Unassigned variables have their own name as their value. This is the default condition
for a variable until you assign it a value. To turn an assigned variable (i.e., a programming variable)
back into an unassigned variable (i.e., a mathematical variable), you must assign it its own name. As
an example:
> # r hasn't been used, so its an unassigned variable:
> r;
r
> # Now make r an assigned variable:
> r := 2;
r := 2
> r;
2
> # Now make r an unassigned variable again:
> r := 'r';
r := r
Maple generally performs what is called "full evaluation" (d.h. die Variable wird in allen Ausdrücken
substituiert).
11.2.6 Functions (Funktionen)
Maple has a large library of functions for you to use. Syntactically, functions are a type of expression.
They have a name, a sequence of zero or more arguments, and they return a value as a result of
calling the function. For example:
> a := -2;
a := -2
> abs(a);
2
> a;
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