ios - How to check NSDictionary values are nil in iPhone -

i have 1 nsdictionary , in dictionary keys , values dynamically added.now want check if value nil set empty string key.how can check this? checking using conditions but, there simple way check nil or empty values.please me,thanks

nsdictionary not hold nil values keys.

if want test presence/absence of specific key's value, can use -objectforkey:. method returns nil if key/value pair absent.

for "empty values", have expand on considered empty value in context of program (e.g. people use nsnull indicate empty value, or if working strings values empty string).