The exists function can be applied to any object. The value returned is the boolean (true or false) associated with the existence of the specified object. If the specified object currently exists (it has been defined, and has not been deleted), the value true is returned; otherwise, the value false is returned.

 

If you have more than one object with the same name, be sure to specify ancestry with the exists function. For example, if you define two graphical regions as follows:

 

graphical region News size 10 30

    at position 40 50 in Profits

    ...

 

graphical region News size 50 50

    at position 15 15 in SalesWindow

    ...

 

and then later specify in your program the function exists, either as:

 

if (exists News in Profits) then ... # with ancestry

 

or as:

 

if (exists News) then ... # without ancestry

 

ESL returns the boolean value true in either case.