iDevOS CALC "VEXISTS" Command

See if an entity exists (name contained in a variable)

Description

CALC( y, src, "VEXISTS" );   // y = exists(src) = does entity name in src exist?

This command checks to see if the entity name given in the text variable src 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 directly can also be tested using "EXISTS".

Parameters

y

Calculation result.
Parameter type: entity name of a numeric variable (eg U8, S32, FLT3 etc).

name

Entity Name.
Parameter type: immediate entity name of a text variable.

"VEXISTS"

CALC command operator.
Parameter type: immediate string.

Examples

Example 1

VAR(res, 0,  U8);  // Result
VAR(name, "test",  TXT);  // Variable to test

// Assume the entity test has not been created.
CALC(res, name, "VEXISTS"); // res = 0

// Create the entity test.
VAR(test, 99,  U8);
CALC(res, name, "VEXISTS"); // res = 1