In Titanic dataset, percentage of missing in each variable

In Titanic dataset, how do I find out the percentage of missingness in each variable?

First convert all character variables into factor variables…for R to treat every variable in the same line…
Then use …any( (titanic))/len (titanic)*100

If you want to find the percentage for column A then :
((Number of null values of A) / Length(A)) *100