User`s guide

Using Functions
V+ provides you with a wide variety of predefined functions for performing string,
mathematical, and general system parameter manipulation. In most cases, you must
provide the data that is input to a function. The function then returns a value based on a
specific operation on that data. Functions can be used anywhere a value or expression would
be used.
Variable Assignment Using Functions
The instruction:
$curr_time = $TIME()
puts the current system time into the variable $curr_time. This is an example of a function
that does not require any input data. The instruction:
var_root = SQRT(x)
puts the square root of the value x into var_root. X is not changed by the function.
Functions Used in Expressions
A function can be used wherever an expression can be used (as long as the data type
returned by the function is the correct type). The instruction:
IF LEN($some_string) > 12 THEN
results in the Boolean expression being true if the string $some_string has more than 12
characters. The instruction:
array_var = some_array[VAL($x)]
results in array_var having the same value as the array cell $x. (VAL converts a string to a
real.)
Functions as Arguments to a Function
In most cases, the values passed to a function are not changed. This not only protects the
variables you use as arguments to a function, but also allows you to use a function as an
argument to a function (so long as the data type returned is the type expected by the
function). The following example results in i having the absolute value of x. (i = D(-22) = 2).
i = SQRT(SQR(x))
Using Functions
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