![]() ![]() ![]() When invoking the function you can choose which parameters you want to provide: The copy() function arguments have all the default values. Val greenFigure = Figure(1, 2, 3) // default color is GREEN In fact, we have seen the use of named arguments with the copy() function for data classes: Val figure = Figure(width = 1, height = 2, length = 3) To improve the readability of such code, you can also use named arguments: What do 1, 2, and 3 mean? The IDE can help us out by rendering the parameter names as hints: When we read this code, it is difficult to immediately figure out what the Figure’s constructor arguments are. Instead of adding a secondary constructor, we can just set a default value for the default color: ![]() With default arguments, we can remove the need for overloading constructors or functions.įor example, let’s say we’d like to create instances of the Figure class from the above example with the default color set to GREEN. See how we only redefine the color in the copy function for the figure? This is a nice introduction to the next two Kotlin features – named and default arguments. Val figure = Figure(1, 2, 3, Color.YELLOW) In addition to equals(), hashCode(), and toString() functions, data classes include a very convenient copy() function and a way to destructure the object into number of variables: The main purpose of data classes is to hold data, and some utility functions are automatically generated for them. ![]() If you need a class to hold some values, data classes are exactly what you need. Let’s start with data classes, which are probably one of the most popular features of Kotlin. So, where do you begin? In this blog post, we would like to highlight some good places to start on the path to learning idiomatic Kotlin. Without them, it is easy to fall back into old Java patterns. To take full advantage of the language and write more concise code, learning Kotlin idioms is a must. However, Kotlin was also designed to improve the developers’ experience by providing a more expressive syntax and a more sophisticated type system. Kotlin was designed to be very similar to Java to make migration as smooth as possible. ![]()
0 Comments
Leave a Reply. |