如何对 Java Hashmap 中的值求和
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/21665538/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to sum values from Java Hashmap
提问by kennechu
I need some help, I'm learning by myself how to deal with maps in Java ando today i was trying to get the sum of the values from a Hashmap but now Im stuck.
我需要一些帮助，我正在自学如何在 Java 中处理地图 ando 今天我试图从 Hashmap 中获取值的总和，但现在我卡住了。
This are the map values that I want to sum.
这是我想要求和的地图值。
HashMap<String, Float> map = new HashMap<String, Float>();
map.put("First Val", (float) 33.0);
map.put("Second Val", (float) 24.0);
Ass an additional question, what if I have 10 or 20 values in a map, how can I sum all of them, do I need to make a "for"?
另一个问题，如果我在地图中有 10 个或 20 个值怎么办，我如何将所有值相加，我需要做一个“for”吗？
Regards and thanks for the help.
问候并感谢您的帮助。
采纳答案by óscar López
If you need to add allthe values in a Map, try this:
如果您需要在 a 中添加所有值Map，请尝试以下操作：
float sum = 0.0f;
for (float f : map.values()) {
sum += f;
}
At the end, the sumvariable will contain the answer. So yes, for traversing a Map's values it's best to use a forloop.
最后，sum变量将包含答案。所以是的，为了遍历 aMap的值，最好使用for循环。
回答by luksch
Float sum = 0f;
for (Float val : map.values()){
sum += val;
}
//sum now contains the sum!
A forloop indeed serves well for the intended purpose, although you could also use a while loop and an iterator...
一个for循环的确很适合在预期目的，但你也可以使用一个while循环和迭代器...
回答by Kuba Spatny
You can definitely do that using a for-loop. You can either use an entry set:
您绝对可以使用for-loop. 您可以使用条目集：
for (Entry<String, Float> entry : map.entrySet()) {
sum += entry.getValue();
}
or in this case just:
或者在这种情况下只是：
for (float value : map.values()) {
sum += value;
}
