But you use such functions in Kotlin from the standard library by default. Environment Kotlin 1.2.0 Empty Empty means no-content. if… Creating an empty String: To create an empty string in Kotlin, we need to create an instance of String class. Kotlin allows developers to assign a sample String and get its length. With the introduction of null safety in Kotlin, everybody now know this special standard function let{...}. Unfortunately, not every API sends valid JSON. Output: Reversed: !maR iH 1. Returns 0 if the object is equal to the specfied object. Input: Hello World Output: dlroW olleH Input: Hi Ram! Few String Properties and Functions. ; compareTo function - compares this String (object) with the specified object. Iterate given string … Kotlin let. 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? A custom serializer for classes, containing many members, is more complex than this workaround. The lambda expression present inside the let is executed only if the variable firstName is not null. Write a Kotlin Program to reverse string with example. I wrote about their difference. To use the nullable type, I use a workaround based on the private serialized string and typed getter/setter. As you can see, String is a non-null type. However, when you want to assign null, the compiler will protest with an error: “Null can not be a value of a non-null type String”. Given a string, we have to check whether it is an empty, blank or NULL string. You probably already heard about them and it's also likely that you even used some of them yet. Functions in Kotlin are very important and it's much fun() to use them. If you look at the code for String.Empty it actual refers to “” in the background so, like @ilogico, I could never understand the reason why some people insisted on using String.Empty instead. = null firstName?.let { println(it.toUpperCase()) } Here, the variable firstName is null, so the lambda expression is not executed to convert the string to Upper Case letters. One special collection of relevant functions can be described as "scope functions" and they are part of the Kotlin standard library: let, run, also, apply and with. Similarly, in Kotlin, I can’t really see why: var variable_name = String() String elements and templates – String Element – The character, digit or any other symbol present in string is called as element of a String. Specifically for this task, I have to swap the name in order to let you implement it yourself. Initialize it with empty string. Program to Reverse a string Pseudo Algorithm. Kotlin String has methods, isBlank() and isEmpty(). This article explores different ways to check if a string is empty or null in Kotlin. The standard approach in Kotlin to check for a null or an empty string … Kotlin program of using let – Now, let’s look at a nullable String type: Example: Input: str = "" Output: True Hence let is inevitably being understood that it is the replacement of null check e.g. isEmpty is the same as comparing to zero string (value let takes the object it is invoked upon as the parameter and returns the result of the lambda expression. val firstName: String? The library actually contains functions isNullOrEmpty, and isNullOrBlank, which checks whether string is null, or empty, or blank. Submitted by IncludeHelp, on April 27, 2020 . Sometimes, it sends an empty string instead null. Use a temp variable result that stores reversed string. 1. isNullOrEmpty() function. Kotlin let is a scoping function wherein the variables declared inside the expression cannot be used outside. 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