Arrays - Crestron SIMPL+ Programming Manual

Software
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20 • SIMPL+
Notice how the constant parts of the string are entered directly. The interesting thing
about the format specification is the %d sequences, which are known as "type
specifiers".
Variable Scope
Variable declarations in a SIMPL+ program can be either global or local. Global
variables are defined in the "Define Variables" section of the code, and "exist"
throughout the entire SIMPL+ program. This means that any event function or user-
defined function can reference and modify global variables. When the value of a
global variable is being set or modified, it is reflected throughout the entire program.
Local variables are defined inside a function declaration and exist only inside that
particular function. In other words, if a local variable, byteCount, were defined inside
of a function, CalcChecksum, any reference to byteCount, outside of the scope of this
function (e.g. in another function) will result in a compiler syntax error. Note that
different functions can use the same variable names when defining local variables.
Take a look at the following example:
// simple function to add up all the bytes in a
// string and append the sum as a single byte
// onto the original string.
String_Function CalcChecksum(STRING argData)
{
INTEGER i, checksum;
checksum = 0;
for (i = 1 to len(argData))
checksum = checksum + byte(argData,i);
return (argData + chr(checksum));
}
In this example, i and checksum are local variables that only exist inside the function,
CalcChecksum. This example also introduces an additional way to implement a local
variable: by passing it as an argument to the function, as was done with the STRING
variable, argData. The concept of local variables and argument passing is discussed
in detail in the section "User-Defined Functions" on page 31.
While the use of global variables may seem simpler, local variables can help keep
your programs better organized and easier to debug. A significant disadvantage of
global variables is that you must be careful each time you use or modify a variable
that it does not have an adverse effect on another part of the program. Since local
variables can only be used inside of a function, this is not a concern.

Arrays

When INTEGER or STRING variables are declared, the user may also declare them
as one- or two-dimensional (INTEGERs only) arrays. An array is a group of data of
the same type arranged in a table. A one-dimensional array can be thought of as a
single row with two or more columns, while a two-dimensional array can be thought
of as a table with multiple rows . In SIMPL+, arrays are declared as follows.
INTEGER myArray1[15]
INTEGER myArray2[10][3] // 2-D integer array with 11x4 elements
STRING myArray3[50][8]
Crestron SIMPL+
// 1-D integer array with 16 elements
// 1-D string array with 9 elements
Programming Guide – DOC. 5789A
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