Covers the Kotlin List methods any, all, and none. If the list doesn’t contain any element defined by the predicate, it will return -1. str1 contains null value and str2 is an empty string. That’s why you don’t need the extra null check. It returns number of elements in a sequence. It requires one more step, list[index], to get the element from the list. This example demonstrates how to Check if Android EditText is empty in Kotlin. This means that behind-the-scenes, Kotlin translates the case element in to collection.contains(element). To check if the argument is in a list: Step 1 − Create a new project in Android Studio, go to File? Nullable Collection For this reason, Kotlin provides the in operator, which is syntactic sugar for the contains() method. 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. str2 is null or empty. In Kotlin we have a huge list of such functions but here we will share some of the most used functions. >>> 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. :] In fact, Kotlin takes null into account when you’re testing for equality in general. indexOf: return the index position of a given value. Note this exclusive works where ‘nullableVariable’ is immutable (i.e. Also, we need to make sure that we do one check before passing the index because for index = -1, it will throw ArrayIndexOutOfBoundsException. 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. Check if LinkedList is empty We can check for emptiness of a LinkedList using isEmpty function. Hence following conditional statement can be used to check if list is empty. isEmpty: boolean value to check if the list is empty or not. Submitted by IncludeHelp, on April 27, 2020 . Kotlin is 100% compatible with all existing Java frameworks, and has good tooling support. Here, you added safe call operators. last: return the last element of the list. 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? 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. In the above program, we've two strings str1 and str2. ... and none. We've also created a function isNullOrEmpty() which checks, as the name suggests, whether the string is null or empty. It’s a pragmatic language with a very low learning curve, and can be quickly grasped by Java developers. Step 2 − Add the following code to res/layout/activity_main.xml. 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. Example: Input: str = "" Output: True In the following example, we check if linkedlist of planets is empty or not and print a … New Project and fill all required details to create a new project. Given a string, we have to check whether it is an empty, blank or NULL string. In Python, empty list object evaluates to false. first: return the first element in the list. str1 is null or empty. size: Return the size of the list. 'Ve two strings str1 and str2 is an empty string empty in...., blank or null string equality in general when you ’ re testing equality! Frameworks, and can be used to check if list is empty in Kotlin here we share. 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