Date.ValueOf not accepting null

 String str = null;

 Date d = Date.valueOf(str);

I am getting the following error when running the above snippet in Anon Apex.

Line: 2, Column: 1

System.NullPointerException: Argument cannot be null.

Resolution:  Using Ternary Operator we can fix the null check

Date d = String.isBlank(str)  ?  null  : Date.valueOf(str);