Language Elements
47
NetLinx Programming Language Reference Guide
Define_function integer MyFunc(INTEGER nFlag)
{
LOCAL_VAR INTEGER n
IF (nFlag > 0)
{
LOCAL_VAR INTEGER n // illegal declaration
.
.
}
.
.
}
Define_function integer MyFunc(INTEGER nFlag)
{
IF (nFlag > 0)
{
LOCAL_VAR INTEGER n
.
.
}
else
{
LOCAL_VAR INTEGER n // legal declaration
}
}
The general form of a static local variable declaration is:
[LOCAL_VAR] [VOLATILE | PERSISTENT] [CONSTANT] [<type>] name
The general form of the non-static local variable declaration is:
[STACK_VAR] [<type>] name
Since non-static local variables are allocated on the program stack (a block of memory reserved for
allocation of temporary variables), the keywords
VOLATILE, PERSISTENT, and CONSTANT do not
apply.
Global variables
Global variables are defined in the DEFINE_VARIABLE section of any program module. For example:
DEFINE_VARIABLE
CONSTANT INTEGER MAXLEN = 64
CHAR STR[MAXLEN] = 'No errors were found.'
INTEGER ARRAY[ ] = {100, 200, 300}
A global variable is accessible throughout the module or program in which it is defined. Global variables
retain their value as long as the program runs. They may retain their value after powering down or
reloading the system, depending on the variable's persistence attributes (
VOLATILE and PERSISTENT).
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