2. UsingArrayList.size() Another way to check if the arraylist contains any element or not, we can check the size of the arraylist. If the list size is greater than zero, then the list is not empty. If the list size is 0, the list is empty. If we look inside theisEmpty()method...
Array is null or emptyArray is not null or emptyCheckArrayArrayValid 在上述状态图中,我们首先进入CheckArray状态,然后根据数组是否为null或者为空进行不同的处理。如果数组为null或者为空,我们将会回到初始状态[*],否则进入ArrayValid状态。 甘特图 下面是一个使用mermaid语法绘制的甘特图,描述了参数校验数组不为空...
/*** Determine whether the given object is an array: * either an Object array or a primitive array. *@paramobj the object to check*/publicstaticbooleanisArray(Object obj) {return(obj !=null&&obj.getClass().isArray()); } /*** Determine whether the given array is empty: * i.e. {...
publicbooleanisArrayNullOrEmpty(Object[]array){if(array==null){// 数组为空returntrue;}if(array.length==0){// 数组为空returntrue;}// 数组不为空returnfalse;} 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 在上面的代码中,我们创建了一个名为isArrayNullOrEmpty的方法,它接受一个Object...
Check if String is Null or Empty in Java Java: Check if String is Numeric How to Convert String to int in Java Reverse a String in Java Convert int to String in Java How to Split a String in Java: Different Examples Convert Char to String in Java ...
/** * The array buffer into which the elements of the ArrayList are stored. * The capacity of the ArrayList is the length of this array buffer. Any * empty ArrayList with elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA * will be expanded to DEFAULT_CAPACITY when the first element is added...
查看ArrayList AddAll源码,由于addAll调用了传入对象的toArray()方法,引起空指针 使用Optional规避空指针时,需要注意些什么 Java8 提供的optional 是什么、定义了哪些方法、日常使用 日常的使用方法有问题吗? 与直接判断是否null几乎一样,所以使用新的API意义不大, ...
(Object o);// 删除LinkedList中第一次出现的指定元素 public E removeLast(); // 删除LinkedList中的最后一个元素 public boolean removeLastOccurrence(Object o);// 删除LinkedList中最后一次出现的指定元素 public int size(); // 获取LinkedList中的元素数量 public Object[] toArray(); // 将LinkedList转化...
public class NullOrEmptyCheckExample { public static void main(String[] args) { String str1 = null; String str2 = ""; String str3 = "Hello, World!"; // Check if str1 is null or empty if (str1 == null || str1.length() == 0) { System.out.println("str1 is null or empty...
Assert.isTrue(Object object,"object must be true")-对象必须为trueAssert.notEmpty(Collection collection,"collection must not be empty")-集合非空 Assert.hasLength(String text,"text must be specified")-字符不为null且字符长度不为0Assert.hasText(String text,"text must not be empty")-text 不为nu...