>>> a=[] # Empty lists evaluate to False >>> if not a: print ("list is empty") else: print ("list is not empty") You can also use len() function. Check if LinkedList is empty We can check for emptiness of a LinkedList using isEmpty function. Submitted by IncludeHelp, on April 27, 2020 . str2 is null or empty. Example: Input: str = "" Output: True It requires one more step, list[index], to get the element from the list. Here, you added safe call operators. To check if the argument is in a list: Note this exclusive works where ‘nullableVariable’ is immutable (i.e. Hence following conditional statement can be used to check if list is empty. New Project and fill all required details to create a new project. Step 2 − Add the following code to res/layout/activity_main.xml. In the following example, we check if linkedlist of planets is empty or not and print a … Given a string, we have to check whether it is an empty, blank or NULL string. This means that behind-the-scenes, Kotlin translates the case element in to collection.contains(element). ... and none. Kotlin is 100% compatible with all existing Java frameworks, and has good tooling support. Covers the Kotlin List methods any, all, and none. If list is null, instead of returning null, you return an empty List, which still adheres to the ... You’ve just told Kotlin that the List can include nulls. Kotlin | Check for empty string: Here, we are going to learn how to check whether a given string is an empty, blank or NULL string in Kotlin programming language? Nullable Collection In the above program, we've two strings str1 and str2. Kotlin code might be compiled not only to JVM bytecode but to JavaScript and Native code as well, but this course is focused on Kotlin/JVM. Also, we need to make sure that we do one check before passing the index because for index = -1, it will throw ArrayIndexOutOfBoundsException. That’s why you don’t need the extra null check. indexOf: return the index position of a given value. We've also created a function isNullOrEmpty() which checks, as the name suggests, whether the string is null or empty. In Python, empty list object evaluates to false. first: return the first element in the list. It’s a pragmatic language with a very low learning curve, and can be quickly grasped by Java developers. str1 contains null value and str2 is an empty string. str1 is null or empty. size: Return the size of the list. This example demonstrates how to Check if Android EditText is empty in Kotlin. :] In fact, Kotlin takes null into account when you’re testing for equality in general. Here is how you can declare a Collection of Nullable Types in Kotlin - val listOfNullableTypes: List = listOf(1, 2, null, 3) // Works To filter non-null values from a list of nullable types, you can use the filterNotNull() function - val notNullList: List = listOfNullableTypes.filterNotNull() 2. isEmpty: boolean value to check if the list is empty or not. It returns number of elements in a sequence. a local property which can’t be altered between the check and the utilization or a member ‘val’ which has a backing field and is not overridable), else it may happen that ‘nullableVariable’ changes to null after the check. Step 1 − Create a new project in Android Studio, go to File? If the list doesn’t contain any element defined by the predicate, it will return -1. last: return the last element of the list. For this reason, Kotlin provides the in operator, which is syntactic sugar for the contains() method. 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