java 检查arraylist是否不为空java
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/28444739/
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
check if arraylist is NOT empty java
提问by Ahmad Ghazi Altarabsheh
I know the isEmpty() method used to check if an arraylist is empty, but I am trying to check if an arraylist is not empty. I tried to look online but I didn't find any useful information on how to do this. My code is like "while ArrayList is not empty then run code).
我知道用于检查数组列表是否为空的 isEmpty() 方法，但我正在尝试检查数组列表是否为空。我试图在网上查看，但没有找到有关如何执行此操作的任何有用信息。我的代码就像“虽然 ArrayList 不为空，然后运行代码）。
回答by David Merinos
Invert the result of isEmpty().
反转 的结果isEmpty()。
public boolean notEmpty(ArrayList a) {
return !a.isEmpty();
}
That will tell you when a list is not empty.
这将告诉您列表何时不为空。
回答by J_fruitty
Alternatively, you can also check whether the array is null by the length/size of the arraylist.
或者，您也可以通过数组列表的长度/大小检查数组是否为空。
while(arrayListName.size() > 0 ){
//execute code
}
回答by Stuart Cardall
If you initialize arrays as nullyou can just check if they are not null:
如果你初始化数组，null你可以检查它们是否不是null：
List<String> myArray = null;
myArray = myFunction.getArrayValues;
if (myArray != null) {
processArray (myArray);
}
回答by Klassic_Pegg
This is easier to read for me
这对我来说更容易阅读
while (arrayList.isEmpty() == false) {
//do something cool
}
