Description: This function attempts to return a valid value given a list of parameters.
Returns: Varies
Usage: Script or steady State
Format: PickValid(Parm1, Parm2 [, Parm3, ...])
Parameters: Parm1, Parm2, Parm3... { varies } { required } { no default: }
Are any number of parameters giving any expressions, from which the first valid value will be selected.
Comments: This function continues its search through its parameter list in order until the first valid value is found.
Examples:
a = Invalid;
b = 83;
c = Invalid;
d = -1;
validAns1 = PickValid(a, b, c, d);
validAns2 = PickValid(a, c, d, b);
The value of validAns1 and validAns2 will be 83 and -1 respectively. A typical use for this function is in setting default values as follows:
<
MyEditfield
(
left;
)
SetDefaults
[
If 1 Main;
[
left = PickValid(left, 100);
]
]
...
>
Given that module MyBox draws a box in the window, adding the PickValid statement ensures that even if an invalid value is given as a parameter, the box will still be displayed, because its invalid parameter will have been replaced with the default value.
See Also: