Variables in POOL
Variables are a way to store data during the program execution. LOGO allows to create a variable in any place
in the code, giving a name to it and optionally an initial value. Variables are not typed, any type can be
assigned to a variable and one variable can store different types during its lifetime.
There are three cathegories of variables that differ in the access scope and access methods:
global and local
variables (known in many LOGO dialects) and shared variables
introduced in POOL.
The instructions make, localmake
and their
synonims allow to create a variable and also to assign a new value to an existing variable. When a name is used
to access a variable, the appropriate variable is selected in the following order:
- local variables are searched, in the order reverse to the order of their creation (variables
created in the most nested function are browsed first);
- then global variables are searched;
- shared variables are searched as the last.
See also:
Data types
Variables, data access
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