weraload.blogg.se - Kotlin list foreach

The lambda is executed for the first element, then the second element, and so on, until it's executed for each element in the collection. This works similarly to the repeat() function, or a for loop. The forEach() function executes the function passed as a parameter once for each item in the collection. The first higher-order function that you learn about is the forEach()function.

Below the Cookie class, outside of main(), create a list of cookies as shown.

Each instance of Cookie represents an item on the menu, with a name, price, and other information about the cookie.

Above the main() function, add the Cookie class.

In the following examples, you'll take a List representing a bakery's cookie menu (how delicious!), and use higher-order functions to format the menu in different ways. forEach() and string templates with lambdas

A web browser with access to the Kotlin Playground.Ģ.

How to use various higher-order functions with the List collection, including forEach(), map(), filter(), groupBy(), fold(), and sortedBy().

How to embed lambda expressions into strings.

Knowledge of various collection types in Kotlin, such as List.

Familiarity with trailing lambda syntax, such as with the repeat() function.

Familiarity with function types and lambda expressions.

In the process, you'll get additional practice working with lambda expressions. In this codelab, you'll learn about a variety of functions that can be used on collection types, including forEach(), map(), filter(), groupBy(), fold(), and sortedBy(). Now that you have a solid foundation working with collections, it's time to revisit higher-order functions. Higher-order functions are especially relevant to collections as they help you perform common tasks, like sorting or filtering, with less code. In the Use function types and lambda expressions in Kotlin codelab, you learned about higher-order functions (functions that call other functions), such as repeat().