Dyota's blog

DAX:  _ = BLANK() and ISBLANK(_) are different!

They really don't behave the same way.

https://dax.guide/blank/

ISBLANK() is more strict. It will only give true for values that are exactly null.

Scenarios

Value equal to blank

Expression Result
NULL = BLANK() true
0 = BLANK() true
"" = BLANK() true

Value and type equal to blank

Expression Result
NULL == BLANK() true
0 == BLANK() false
"" == BLANK() false

IS blank

Expression Result
ISBLANK(NULL) true
ISBLANK(0) false
ISBLANK("") false