Exoskeleton of cicada attached to Tridax procumbens. An exoskeleton (from Greek Î­Î¾Ï, Ã©xÅ outer and ÏÎºÎµÎ»ÎµÏÏÏ, skeletos skeleton) is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton (endoskeleton) of, for example, a human. In usage, some of the larger kinds of exoskeletons are known as shells.
The term arbitrary here refers to the fact that the symbol that people use is made or chosen without any principle, logic or reason. For example, people in Java do not have a principle or logic to call an animal with long tail, two hands, and two legs and like scratching and playing on trees as kethek.o, to answer Daniel's question: English people do not have any reason why they call the animal that produces meauwww as cat. Again, this is because language is arbitrary: no logical reason is used when choosing a symbol, and no direct relationship between the symbol and the symbolized.
Many symbols are simply methods of a class, a trait, or an object. For instance, if you do. Youâll find the method ++ right on the ScalaDoc for List. However, thereâs one convention that you must be aware when searching for methods.Methods ending in colon (:) bind to the right instead of the left.ethods provided by implicit conversion. If you did not find the symbol you are looking for in the list of reserved symbols, then it must be a method, or part of one. But, often, youâll see some symbol and the documentation for the class will not have that method.