Scala 与Java

Java是一种通用的计算机编程语言，它是并发的、基于类的、面向对象的等Java应用程序被编译为可以在任何Java虚拟机 (JVM) 上运行的字节码，而与计算机架构无关。

Scala 是一种通用的、高级的、多范式的编程语言。它是一种纯面向对象的编程语言，也为函数式编程方法提供支持。没有原始数据的概念，因为在 Scala 中一切都是对象。它旨在以一种精炼、简洁和类型安全的方式表达一般编程模式。

以下是 Scala 和Java之间的一些主要区别：

Scala	Java
Scala is a mixture of both object oriented and functional programming.	Java is a general purpose object oriented language.
Scala is less readable due to nested code.	Java is more readable.
The process of compiling source code into byte code is slow.	The process of compiling source code into byte code is fast.
Scala support operator overloading.	Java does not support operator overloading.
Scala supports lazy evaluation.	Java does not support lazy evaluation.
Scala is not backward compatible.	Java is backward compatible means the code written in the new version can also run in older version without any error.
Any method or function present is Scala are treated like they are variable.	Java treats functions as an object.
In Scala, the code is written in compact form.	In Java, the code is written in long form.
Scala variables are by default immutable type.	Java variables are by default mutable type.
Scala treated everything as an instance of the class and it is more object oriented language as compare to Java.	Java is less object oriented as compare to Scala due to presence of primitives and statics.
Scala does not contain static keyword.	Java contains static keyword.
In Scala, all the operations on entities are done by using method calls.	In Java, operators are treated differently and is not done with method call.