Identifier normalization: Why is the micro sign converted into the Greek letter mu?

There are two different characters involved here. One is the MICRO SIGN, which is the one on the keyboard, and the other is GREEK SMALL LETTER MU. To understand what’s going on, we should take a look at how Python defines identifiers in the language reference: identifier ::= xid_start xid_continue* id_start ::= <all characters in … Read more

Hibernate throws org.hibernate.AnnotationException: No identifier specified for entity: com..domain.idea.MAE_MFEView

You are missing a field annotated with @Id. Each @Entity needs an @Id – this is the primary key in the database. If you don’t want your entity to be persisted in a separate table, but rather be a part of other entities, you can use @Embeddable instead of @Entity. If you want simply a … Read more

What are “connecting characters” in Java identifiers?

Here is a list of connecting characters. These are characters used to connect words. http://www.fileformat.info/info/unicode/category/Pc/list.htm U+005F _ LOW LINE U+203F ‿ UNDERTIE U+2040 ⁀ CHARACTER TIE U+2054 ⁔ INVERTED UNDERTIE U+FE33 ︳ PRESENTATION FORM FOR VERTICAL LOW LINE U+FE34 ︴ PRESENTATION FORM FOR VERTICAL WAVY LOW LINE U+FE4D ﹍ DASHED LOW LINE U+FE4E ﹎ CENTRELINE … Read more

Using number as “index” (JSON)

JSON only allows key names to be strings. Those strings can consist of numerical values. You aren’t using JSON though. You have a JavaScript object literal. You can use identifiers for keys, but an identifier can’t start with a number. You can still use strings though. var Game={ “status”: [ { “0”: “val”, “1”: “val”, … Read more

dollar sign in variable name?

The only legal characters according to the standard are alphanumerics and the underscore. The standard does require that just about anything Unicode considers alphabetic is acceptable (but only as single code-point characters). In practice, implementations offer extensions (i.e. some do accept a $) and restrictions (most don’t accept all of the required Unicode characters). If … Read more