在 Scala 中省略等号的方法会变成什么?

本文介绍了在 Scala 中省略等号的方法会变成什么?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我刚刚发现在 Scala 中定义方法时可以不使用 = 符号.

I've just found out that it's possible not to use the sign of = when defining a method in Scala.

def someMethod(a: Int) { println(a) println("---------") }

上面的版本和参数列表后面加等号和大括号{有什么区别?

What's the difference between the above version and one with the equals sign after the parameter list and the opening curly bracket {?

推荐答案

这样的方法定义被称为procedure.这是 Unit 返回方法的特殊语法:

Such method definition is called procedure. It's a special syntax for Unit-returning methods:

def someMethod(a: Int): Unit = { println(a) println("---------") }

这不是推荐的语法.Martin Odersky 认为包含这种语法是一个错误的决定.请参阅主题演讲 - Scala 风格第 45 章.

It's not a recommended syntax. Martin Odersky believes it was a bad decision to include this syntax. See Keynote - Scala with Style chapter 45.