Groovy中动态添加元素到ArrayList [英] Dynamically adding elements to ArrayList in Groovy

问题描述

我是 Groovy 的新手，尽管阅读了很多关于此的文章和问题，但我仍然不清楚发生了什么.根据我目前的理解，当您在 Groovy 中创建一个新数组时，底层类型是 Java ArrayList.这意味着它应该是可调整大小的，您应该能够将其初始化为空，然后通过 add 方法动态添加元素，如下所示:

I am new to Groovy and, despite reading many articles and questions about this, I am still not clear of what is going on. From what I understood so far, when you create a new array in Groovy, the underlying type is a Java ArrayList. This means that it should be resizable, you should be able to initialize it as empty and then dynamically add elements through the add method, like so:

MyType[] list = []
list.add(new MyType(...))

此编译，但在运行时失败:没有方法签名:[LMyType;.add() 适用于参数类型:(MyType) 值:[MyType@383bfa16]

This compiles, however it fails at runtime: No signature of method: [LMyType;.add() is applicable for argument types: (MyType) values: [MyType@383bfa16]

执行此操作的正确方法或正确类型是什么?

What is the proper way or the proper type to do this?

推荐答案

Groovy 的方法是

The Groovy way to do this is

def list = []
list << new MyType(...)

创建一个列表并使用重载的 leftShift 操作符附加一个项目

which creates a list and uses the overloaded leftShift operator to append an item

请参阅 Groovy 列表上的文档以获取大量示例.

See the Groovy docs on Lists for lots of examples.

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