scala study

以前没使用过Scala, 其实我Java也是半截水平\无奈, 学Java的时候刚从C++中挣脱出来,发现Java无比优雅,但很快又对Java种种不信任程序员的设计感到受限. 直到, , 今天遇到了Scala\撒花 Scala的collection设计不能更赞!一段时间后打算专门写篇文章总结Scala,名字就叫"我为什么喜欢Scala!". 废话就不多说了,今天研究了一下Scala的override用法与特点. override --- one of the key words of S

1. Unified Type System Scala has a unified type system, enclosed by the type Any at the top of the hierarchy and the type Nothing at the bottom of the hierarchy. All Scala types inherit from Any. # Using Any, Book extends AnyRef, and x is an Int that

1. Translating Java Classes to Scala Classes Example 1: # a class declaration in Java public class Book{} # Scala equivalent of a class declaration class Book Example 2: # a Java class with a Construtor public class Book{ private final int isbn; priv

Scala's object-oriented collections support mutable and immutable type hierarchies. Also support functional higher-order operations such as map, filter, and reduce that let you use expression-oriented programming in collections. Higher-order operatio

The basic functional cornerstones of Scala: immutable data types, passing of functions as parameters and pattern matching. 1. Basic Pattern Matching In Scala, your cases can include types, wildcards, sequences, regular expressions, and so forth. scal

A trait provides code reusability in Scala by encapsulating method and state and then offing possibility of mixing them into classes thus allowing code reuse. #define Trait Gliding scala> trait Gliding{ | def gliding(){ println("gliding")} |

1. Functional programming treats computation as the evaluation of mathematical and avoids state and mutable data. Scala encourages an expression-oriented programming(EOP) 1) In expression-oriented programming every statement is an expression. A state

1. Variables (1) Three ways to define variables: 1) val refers to define an immutable variable; scala> val x = 10 x: Int = 10 scala> x*x res4: Int = 100 scala> res4 + 1 # use result as a value res6: Int = 101 scala> res4 + res6 res7: Int = 201

1. The three principles of OOP are encapsulation(封装性), inheritance(继承性) and polymorphism(多态性). example: class Shape{ def area: Double = 0.0 } # supertype # subtypes class Rectangle(val width: Double, val height: Double) extends Shape{ override def ar