方法isEmpty()在Java中做什么？
如果此列表不包含任何元素，则类java.util.ArrayList 的 isEmpty()方法返回true。
示例
import java.util.ArrayList;
public class ArrayListDemo {
public static void main(String[] args) {
ArrayList<Integer> arrlist = new ArrayList<Integer>(5);
arrlist.add(25);
arrlist.add(10);
arrlist.add(20);
arrlist.add(35);
boolean retval = arrlist.isEmpty();
if (retval == true) {
System.out.println("list is empty");
} else {
System.out.println("list is not empty");
}
for (Integer number : arrlist) {
System.out.println("Number = " + number);
}
}
}输出结果
list is not empty Number = 25 Number = 10 Number = 20 Number = 35