java 如何在java中检查元素是否为空
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How to check element is not null in java
提问by user441978
filterItems = null;
filterItems = new ArrayList<SelectItem>();
Iterator<String> it = RefListMap.keySet().iterator();
while (it.hasNext()) {
String s = (String) it.next();
filterItems.add(new SelectItem(s, s));
}
Now i am getting filterItems size=1 but that value is null.How to check array element is not equal to null.
现在我得到 filterItems size=1 但该值为空。如何检查数组元素不等于空。
if(filterItems != null)
{
code
}
but this condition is not working...Please help me.
但这种情况不起作用...请帮助我。
回答by jjczopek
try:
尝试：
String s = (String) it.next();
if(s != null){
filterItems.add(new SelectItem(s, s));
}
回答by crazyscot
Presumably the value you're getting from the RefListMapis null. You might check whether swas null before you add it to filterItems.
据推测，您从 中获得的RefListMap值为空。您可能要检查是否s为空，你将它添加到以前filterItems。
