How can I design a class named allergy?

1 requirement: design a class named allergy that provides information about the allergy of a patient. e.g. who reported the allergy(patient/doctor/relative), different symptoms of the allergy that are detected, severity, method that returns when was that allergy detected in that patient. I am thinking of something like this: Is this a good design of the … Read more

How do you count the elements of an array in java

What do you mean by “the count”? The number of elements with a non-zero value? You’d just have to count them. There’s no distinction between that array and one which has explicitly been set with zero values. For example, these arrays are indistinguishable: Arrays in Java always have a fixed size – accessed via the length field. There’s no concept of … Read more

How to convert java.util.Date to java.sql.Date?

tl;dr How to convert java.util.Date to java.sql.Date? Don’t. Both Date classes are outmoded. Sun, Oracle, and the JCP community gave up on those legacy date-time classes years ago with the unanimous adoption of JSR 310 defining the java.time classes. Use java.time classes instead of legacy java.util.Date & java.sql.Date with JDBC 4.2 or later. Convert to/from java.time if inter-operating with code not yet updated to java.time. Legacy Modern Conversion java.util.Date java.time.Instant java.util.Date.toInstant()java.util.Date.from( … Read more