java check if null or empty

The if condition will execute if my_var is any value other than a null i.e . To reason about this, let's say that our article has an Optional<Date>, holding the date when published. If you want to check whether the string is empty/null/undefined, use the following code: In my both undergraduate and post-graduate (Information System) courses, I did some simple Java work such as dynamic price modelling (simple command line Java app) and a booking system (JSP and servlets). Program to check the string is null or empty. C#'s String.IsNullOrWhiteSpace, and the answer above, will return true for null, empty string, and "\t \r\n". How to check if a Variable Is Not Null in JavaScript Output. The problem is that int and long are primitives. How to check if JSON content is null (or empty)? If you use the Apache Commons Collections library in your project, you may use the CollectionUtils.isEmpty and MapUtils.isEmpty () methods which respectively check if a collection or a map is empty or null (i.e. If we look inside the isEmpty () method, it also check the size of arraylist to . Example 3 - Check if Array is Empty using Null Check on Elements. This method returns true if the string is empty ( length () is 0), and false if not. How to check empty rows in excel using java | javakeypoint This post will discuss how to check if a string is empty or null in Java. Advantages: Consistency in the null check code. Java: check for null or allow exception handling - Stack Overflow It returns an object of class User1, which we later store in getUser1Object. The isEmpty () method returns a boolean value that indicates whether the map contains no elements. If we use the map function, we'll end up with a nested Optional. If the list size is greater than zero, then list is not empty. java check if int value is null or empty code example A list contains numbers and null values. You can clearly see that there is a string str3 with empty spaces and it returns false because it does not come under the empty check and . if (str != null && !str.isEmpty ()) Be sure to use the parts of && in this order, because java will not proceed to evaluate the second part if the first part of && fails, thus ensuring you will not get a null pointer exception from str.isEmpty () if str is null.