Is not Defined versus Is not populated

[john_gautreau]

Hi -

when writing conditional logic on a Set Data Values extension, what is the difference between "is not defined" and "is not populated"?

I would like to set something like this...

set variable_A (js_page) to variable_B (UDO var)

when variable_A (js_page) is not set

AND variable_B (UDO var) is set

thanks, John

[dan_george]

@john_gautreau

Is not defined means the variable is declared. Whether or not its value is empty is not of importance. An example of a defined variable is:

var variable_A;

Is not populated means that variable is declared AND that it has a value. An example of a populated variable is:

var variable_A="test";

In your case I would do:

set variable_A (js_page) to variable_B (UDO var)

when variable_A (js_page) is not defined

AND variable_B (UDO var) is defined

AND variable_B (UDO var) is populated

This will ensure variable_B exists with a valid value before updating variable_A.

Cheers,

-Dan

[Yoosuf]

To give a more technical response to your question I would say,

Is Not Defined would be evaluated as,

(typeof d['your_variable_here'] == 'undefined')

and Is Not Populated would be evaludated as,

(typeof d['your_variable_here'] != 'undefined' && d['your_variable_here'] == '')

[john_gautreau]

great - thank you

[john_gautreau]

thank you

[TealiumJustin]

@john_gautreau @Yoosuf @dan_george

To add on to the other answers: the actual JavaScript code generated by each condition is documented here: Generated JavaScript Code for Load Rule/Extension Conditions