如何通过构造初始化HashSet值？ [英] How to initialize HashSet values by construction?

问题描述

我需要用初始值创建设置。

 设置< String> h = new HashSet< String>（）; 
 h.add（a）; 
 h.add（b）;有一种方法可以在一个命令中做到这一点？
 
 
解决方案
有一个我用的速记不是很有效率，但适合单行：
 设置< String> h = new HashSet< String>（Arrays.asList（a，b））; 
  
同样，这不是时间效率，因为你正在构造一个数组，转换为列表， 
 
 
 
初始化静态最终集时，我通常这样写：
  public static final String [] SET_VALUES = new String [] {a，b}; 
 public static final Set< String> MY_SET = new HashSet< String>（Arrays.asList（SET_VALUES））; 
  
稍微不那么丑陋和效率对静态初始化无关紧要。
 
I need to create a Set with initial values.
Set<String> h = new HashSet<String>();
h.add("a");
h.add("b");
Is there a way to do this in one command?
解决方案
There is a shorthand that I use that is not very time efficient, but fits on a single line:
Set<String> h = new HashSet<String>(Arrays.asList("a", "b"));
Again, this is not time efficient since you are constructing an array, converting to a list and using that list to create a set.

When initializing static final sets I usually write it like this:
public static final String[] SET_VALUES = new String[] { "a", "b" };
public static final Set<String> MY_SET = new HashSet<String>(Arrays.asList(SET_VALUES));
Slightly less ugly and efficiency does not matter for the static initialization.

                        
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