csmstr - Omega Engineering

PROGRAMMING TIPS
CRIMSON USER MANUAL - MODULAR CONTROLLER
too intimidating, a series of if statements can be used instead to produce the same results, but
with marginally lower performance, and somewhat less readability.)
LOCAL VARIABLES
Some programs use variables to store intermediate results, or to control one of the various
loop constructs described below. Rather than defining a tag to hold these values, you can
declare what are known as local variables using the syntax shown below…
int a; // Declare local integer ‘a’
float b; // Declare local real ‘b’
cstring c;
// Declare local string ‘c’
Local variables may optionally be initialized when they are declared by following the variable
name with := and the value to be assigned. Variables that are not initialized in this manner
are set to zero, or an empty string, as appropriate.
Note that local variables are truly local in both scope and lifetime. This means that they
cannot be referenced outside the program, and they do not retain their values between
function invocations. If a function is called recursively, each invocation has its own variables.
LOOP CONSTRUCTS
The three different loop constructs can be used to perform a given section of code while a
certain condition is true. The while loop tests its condition before the code is executed, while
the do loop tests the condition afterwards. The for loop is a quicker way of defining a while
loop, allowing you to combine three common elements into one statement.
You should note that some care is required when using loops within your programs, as you
may make a programming error which results in a loop that never terminates. Depending on
the situation in which the program is invoked, this may seriously disrupt the Master’s user
interface activity, or its communications. Loops which iterate too many times may also cause
performance issues for the subsystem that invokes them.
THE WHILE LOOP
This type of loop repeats the action that follows it while the condition in the while statement
remains true. If the condition is never true, the action will never be executed, and the loop
will perform no operation beyond evaluating the controlling condition. If you want more than
one action to be included in the loop, be sure to surround the multiple statements in curlybrackets,
as with the if statement. The example below initializes a pair of local variables, and
then uses the first to loop through the contents of an array, totaling the first ten elements, and
returning the total value to the caller…
The architecture of the while loop statement is as follow…
while ( condition ){
Action;
}
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