iDevOS CALC "EXISTS" Command
See if an entity exists (immediate name).
Description
CALC( y, name, "EXISTS" ); // y = exists("name") = does entity name exist?
This command checks to see if the given entity called name
exists, ie has been created. The value y
will be set to 1
if the entity exists or 0
if it does not.
A test for the existence of an entity whose name is provided in a text variable can also be tested using "VEXISTS"
.
Parameters
y
- Calculation result.
Parameter type: entity name of a numeric variable (egU8
,S32
,FLT3
etc). name
- Entity Name.
Parameter type: immediate entity name. "EXISTS"
- CALC command operator.
Parameter type: immediate string.
Examples
Example 1
VAR(res, 0, U8); // Result // Assume the entity test has not been created. CALC(res, test, "EXISTS"); // res = 0 // Create the entity test. VAR(test, 99, U8); CALC(res, test, "EXISTS"); // res = 1