Ruby (programming language)
Matsumoto defined it this way in an interview:Ruby is object-oriented: every value is an object, including classes and instances of types that many other languages designate as primitives (such as integers, booleans, and "null"). Variables always hold references to objects. Every function is a method and methods are always called on an object. Methods defined at the top level scope become methods of the Object class. Since this class is an ancestor of every other class, such methods can be called on any object. They are also visible in all scopes, effectively serving as "global" procedures. Ruby supports inheritance with dynamic dispatch, mixins and singleton methods (belonging to, and defined for, a single instance rather than being defined on the class). Though Ruby does not support multiple inheritance, classes can import modules as mixins.
Equals sign
In Ruby, equality under codice_12 requires both operands to be of identical type, e.g. codice_9 is false. The codice_8 operator is flexible and may be defined arbitrarily for any given type. For example, a value of type codice_21 is a range of integers, such as codice_22. codice_23 is false, since the types are different (Range vs. Integer); however codice_24 is true, since codice_8 on codice_21 values means "inclusion in the range". Note that under these semantics, codice_8 is non-symmetric; e.g. codice_28 is false, since it is interpreted to mean codice_29 rather than codice_30.