$Data()

$Data()

Returns an integer code describing the value and descendent status of a local or global variable.

The format for the $DATA function is:

$D[ATA](glvn)

• The subscripted or unsubscripted global or local variable name specifies the target node.
• If the variable is undefined, $DATA() returns 0.
• If the variable has a value but no descendants, $DATA() returns 1.
• If the variable has descendants but no value, $DATA() returns 10.
• If the variable has a value and descendants, $DATA() returns 11.
• $ZDATA() extends $DATA() to reflects the current alias state of the lvn or name argument to identify alias and alias container variables. For more information, refer to “$ZDATA()”.

The following table summarizes $DATA() return values.

$DATA() return values can also be understood as a pair of truth-values where the left describes descendants and the right describes data 1 and where M suppresses any leading zero (representing no descendants).

Examples of $DATA()

Example:

GTM>Kill  Write $Data(a)
0
GTM>Set a(1)=1 Write $Data(a(1))
1
GTM>Write $Data(a)
10
GTM>Set a=0 Write $Data(a)
11
GTM>

This uses $DATA to display all possible $DATA() results.

Example:

lock ^ACCT(0)
if '$data(^ACCT(0)) set ^ACCT(0)=0
set (ACCT,^ACCT(0))=^ACCT(0)+1
lock

This uses $DATA() to determine whether a global node requires initialization.

Example:

for  set cus=$O(^cus(cus)) quit:cus=""  if $data(^(cus))>1 do WORK

This uses $DATA() to determine whether a global node has descendants and requires additional processing.