Java的foreach循环保持顺序吗？ [英] Does Java's foreach loop preserve order?

问题描述

Java的foreach循环从第一个对象开始，并以线性方式工作到最后？例如

  String [] names = new String [] {Zoe，Bob，Charlie，Alex }; 
 for（String name：names）{
 // do stuff ... 
} 
  

字符串Zoe总是先处理，然后是Bob等？没有排序发生？我已经测试了自己，并没有找到任何，但我需要一个保证，并找不到任何文档。

解决方案

是。订单没有改变。这适用于所有类型的 Java集合框架实现迭代器接口 for循环使用。如果你想排序你的数组，你可以使用 Arrays.sort（names）

Does Java's foreach loop start at the first object and in a linear fashion work it's way to the end? For example

String[] names = new String[] {"Zoe", "Bob", "Charlie", "Alex"};
for(String name : names) {
  //do stuff...
}

Is the string "Zoe" always processed first, followed by "Bob" etc? No sorting happens? I've tested it out myself and haven't found any but I need a guarantee and couldn't find anything in the docs.

解决方案

Yes. The order is not changed. This applies to all types of collections of the Java Collection Framework implementing the iterator interface that is used by the for-loop. If you want to sort your Array, you can use Arrays.sort(names)

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