使用 Java 8 中的特性，转换列表所有值的最简洁方法是什么？
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Using the features in Java 8, what is the most concise way of transforming all the values of a list?
提问by The Coordinator
Using the new features of Java 8, what is the most concise way of transforming all the values of a List<String>?
使用 Java 8 的新特性，转换 a 的所有值的最简洁方法是List<String>什么？
Given this:
鉴于这种：
List<String> words = Arrays.asList("Apple", "Ananas", "Mango", "Banana", "Beer");
I am currently doing this:
我目前正在这样做：
for (int n = 0; n < words.size(); n++) {
words.set(n, words.get(n).toUpperCase());
}
How can the new Lambdas, Collections and Streams API in Java 8 help:
Java 8 中新的 Lambdas、Collections 和 Streams API 如何提供帮助：
transform the values in-place (without creating a new list)
transform the values into a new result list.
就地转换值（无需创建新列表）
将值转换为新的结果列表。
采纳答案by The Coordinator
This is what I came up with:
这就是我想出的：
Given the list:
鉴于名单：
List<String> keywords = Arrays.asList("Apple", "Ananas", "Mango", "Banana", "Beer");
(1) Transforming them in place
(1) 就地改造
Maybe I am missing it, there does not seem to be a 'apply' or 'compute' method that takes a lambda for List. So, this is the same as with old Java. I can not think of a more concise or efficient way with Java 8.
也许我错过了它，似乎没有一个“应用”或“计算”方法可以为 List 使用 lambda。因此，这与旧 Java 相同。我想不出更简洁或有效的 Java 8 方法。
for (int n = 0; n < keywords.size(); n++) {
keywords.set(n, keywords.get(n).toUpperCase());
}
Although there is this way which is no better than the for(..) loop:
虽然有这种方式并不比 for(..) 循环好：
IntStream.range(0,keywords.size())
.forEach( i -> keywords.set(i, keywords.get(i).toUpperCase()));
(2) Transform and create new list
(2) 转换并创建新列表
List<String> changed = keywords.stream()
.map( it -> it.toUpperCase() ).collect(Collectors.toList());
回答by jsrmalvarez
Maybe using the new stream concept in collections:
也许在集合中使用新的流概念：
List<String> keywords = Arrays.asList("Apple", "Ananas", "Mango", "Banana", "Beer");
//(1)
keywords = keywords.stream().map(s -> s.toUpperCase()).collect(Collectors.toList());
//(2)
List<String> uppercaseKeywords = keywords.stream().map(s -> s.toUpperCase()).collect(Collectors.toList());
