freelanceshack.com
-
6 min readTo upload an array to a MySQL database in Kotlin, you can use the JDBC library to establish a connection with the database. Once the connection is established, you can create a PreparedStatement and use it to insert the array values into the database table.First, create a connection to the MySQL database using the JDBC driver and specify the database URL, username, and password. Then, prepare an SQL query that inserts values into the table with placeholders for the array elements.
-
7 min readUse Sequence in Kotlin when you have a potentially large or infinite collection of data that you want to process lazily. Sequences allow for more efficient processing of data, as they only evaluate elements as needed. Lists, on the other hand, are eager collections that store all elements in memory at once, which can be inefficient for large datasets. Consider using Sequence when dealing with data streams, database queries, or other scenarios where lazy evaluation is preferred.
-
3 min readTo pass any enum as a function argument in Kotlin, you simply need to declare the parameter type of the function as the enum class. For example, if you have an enum class called Colors and a function that takes a Colors enum as an argument, you would define the function like this: enum class Colors { RED, BLUE, GREEN } fun printColor(color: Colors) { println("The selected color is $color") } fun main() { val selectedColor = Colors.
-
5 min readTo fill a 2D array with random numbers in Kotlin, you can use nested loops to iterate over each row and column of the array. Within the loops, you can generate a random number using the Random class from the kotlin.random package. Then, you can assign this random number to the corresponding element in the 2D array. Here's an example code snippet: import kotlin.random.
-
6 min readTo validate a class string property is not empty in Kotlin, you can use the following approach:You can check if the string property is not null and not empty by using the isNullOrEmpty() function provided by Kotlin's standard library. Here's an example: class MyClass(val name: String) { init { require(name.isNotEmpty()) { "Name must not be empty" } } } In this example, the class MyClass ensures that the name property is not empty when an instance is created.
-
3 min readIn Kotlin, objects are singleton instances of a class. They are defined using the "object" keyword instead of the "class" keyword. To get object support in Kotlin, you simply need to create an object using the "object" keyword and define the properties and methods needed for that object. Objects can also implement interfaces and extend classes like regular classes.
-
3 min readTo add a button event in a Kotlin fragment, you can follow these steps:In the fragment layout file (e.g. fragment_layout.xml), define a Button element with an ID that you can reference in your Kotlin code. In the Kotlin file for the fragment (e.g. MyFragment.kt), reference the button by using the findViewById() method and assign it to a variable. Set an onClickListener for the button variable by using the setOnClickListener() method.
-
4 min readTo make an API request call in the application class in Kotlin, you can use libraries like Retrofit or OkHttp. First, create an instance of the Retrofit or OkHttpClient class in your application class. Then, create a service interface that defines the API endpoints and methods for making the requests. Finally, use the Retrofit or OkHttpClient instance to create and execute API requests in your application class.
-
6 min readTo use hours, minutes, and seconds in delay using Kotlin, you can create a delay function that takes the duration in milliseconds as a parameter. To convert hours, minutes, and seconds to milliseconds, you can use the following formula:delayInMillis = (hours * 3600000) + (minutes * 60000) + (seconds * 1000)You can then use this delayInMillis value as the parameter for the delay function to pause the execution of your code for the specified duration.
-
5 min readTo choose all components in a RecyclerView using Kotlin, you can iterate through all the items in the RecyclerView and select each one programmatically. You can achieve this by keeping track of the selected items in a list or set, and updating the selection status of each item as the user interacts with them.You can also implement a "Select All" button that, when clicked, selects all items in the RecyclerView by updating the selection status of each item.
-
6 min readTo make a download progress indicator in Kotlin, you can use a ProgressBar view in your layout file to visually represent the progress of the download. In your Kotlin code, you can update the progress of the download by setting the progress attribute of the ProgressBar view. You can track the progress of the download by using a download manager or by calculating the percentage of the file downloaded.