java - Is there any difference between == null and .equals("null")? -


i confused following code. why compare both == , equals method?

(validfolderrow.getbondtafoldertype() == null || validfolderrow.getbondtafoldertype().equals("null"))

what's difference between equals() , ==?

can tell me difference between

validfolderrow.getbondtafoldertype() == null

and 

validfolderrow.getbondtafoldertype().equals("null")

?

validfolderrow.getbondtafoldertype() == null compares null (i.e. checks if validfolderrow.getbondtafoldertype() null). validfolderrow.getbondtafoldertype().equals("null") compares validfolderrow.getbondtafoldertype() string value "null".

note first comparison must done first, since if validfolderrow.getbondtafoldertype() null, can't call equals on (since throw nullpointerexception). since || short circuit operator, evaluating first operand true prevent second operand being evaluated.


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