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).
5 Answers
Invert the result of isEmpty().
public boolean notEmpty(ArrayList a) {
return !a.isEmpty();
}
That will tell you when a list is not empty.
2 Comments
Jean-François Savard
why do a method call, when you can directly do !list.isEmpty() ?
HJW
I prefer to call it negate.
Alternatively, you can also check whether the array is null by the length/size of the arraylist.
while(arrayListName.size() > 0 ){
//execute code
}
Comments
If you initialize arrays as null you can just check if they are not null:
List<String> myArray = null;
myArray = myFunction.getArrayValues;
if (myArray != null) {
processArray (myArray);
}
Comments
This is easier to read for me
while (arrayList.isEmpty() == false) {
//do something cool
}
Comments
Can be useful
if (!arrayList.isEmpty() ){
//execute code
System.out.println(arrayList.get(arrayList.size()-1));
}
while(!myList.isEmpty())?