In application programming, it is advisable to check both if list is not null and then not empty. If list is not initialized, we may getNullPointerExceptionin runtime. 2. UsingArrayList.size() Another way to check if the arraylist contains any element or not, we can check the size of ...
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演示isEmpty()在Java中工作的程序: // Java code to demonstrate the working of//isEmpty() method in List interfaceimportjava.util.*;publicclassGFG{publicstaticvoidmain(String[] args){// creating an Empty Integer ListList<Integer> arr =newArrayList<Integer>(10);// check if the list is empty...
Learn tocheck if a directory is empty, or contains any files, in Java using NIO APIs. 1. UsingFiles.list() TheFiles.list(dirPath)returns a lazily populatedStreamof files and directories(non-recursive) in a given path. We can use thestream.findAny()method thatreturns an emptyOptionalif th...
When working with strings in Java, it is essential to check if a string is null or empty. A null string refers to the absence of any value, while an empty string is a string with zero characters. Failing to handle null or empty strings appropriately can lead to unexpected errors and ...
There are two ways to empty an ArrayList - By using ArrayList.clear() method or with the help of ArrayList.removeAll() method. Although both methods do the same task the way they empty the List is quite different. Lets see the below example first then we
Check if a list is empty: import java.util.ArrayList; public class Main { public static void main(String[] args) { ArrayList<String> cars = new ArrayList<String>(); System.out.println(cars.isEmpty()); cars.add("Volvo"); cars.add("BMW"); cars.add("Ford"); cars.add("Mazda"); ...
Check out our in-depth guide on JUnit assertionshere. All these assertions, when failed, will return anAssertionError. 4. Using Hamcrest Core Hamcrestis a well-known framework providing matchers that are commonly used for unit testing in the Java ecosystem. ...
Check if a string is null or empty in XSLT 多条件查询 string.Format("/root/deviceList//item/guid[{0}]", strBuilder.ToString()) "/root/deviceList//item/guid[text()=\"h\" or text()=\"a\" or text()=\"c\"]"谓词嵌套var nodes = xmlDoc.SelectNodes(string.Format("/root/device...
This post will discuss how to filter null, empty, and blank values from a list in Java. In plain Java, you can use Stream API to filter null, empty, and blank values from a list.