常规创建Arraylist和Hashmap有哪些不同的方法 [英] what are the different ways to create an Arraylist and Hashmap in groovy

问题描述

  def list = new ArrayList（）
  c $ c> 

但是，codenarc报告中显示的警告如下。



  ArrayList对象最好使用形式[] as ArrayList
  

是实例化集合的更好方法吗？

解决方案

您可以这样做：



  def list = [] //默认是ArrayList 
 def list = [] as ArrayList 
 ArrayList list = [] 
  

同样，对于 HashMap ：

  HashMap map = [：] 
 def map = [：] as HashMap 
  

这种情况下的默认值是 LinkedHashMap ：



  def map = [：] 
  




I have created an ArrayList like the following:

def list = new ArrayList()

But the codenarc report it is warning like following.

ArrayList objects are better instantiated using the form "[] as ArrayList"

What are the better ways to instantiate the collections?

解决方案

You can do:

def list = []               // Default is ArrayList
def list = [] as ArrayList
ArrayList list = []

And again, for HashMap:

HashMap map = [:]
def map = [:] as HashMap

The default in this case is a LinkedHashMap:

def map = [:] 

这篇关于常规创建Arraylist和Hashmap有哪些不同的方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！