Android (19) 썸네일형 리스트형 MutableList * sum() The examples show you how to use sum() function to: sum of all items in the normal List sum of specific field in List of Objects (in need of map()) sum of specific field of all values in a Map (in need of map()) Why we need map()? map() will create a List of quantity first, then we invoke: List.sum() List We’re gonna use sum() on List and List for example. val nums = listOf(10, 20, 30) p.. Set up for coroutine ext.coroutineVersion = '1.0.0' // official version // for coroutine implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutineVersion" Set up for Rxkotlin implementation 'io.reactivex.rxjava2:rxandroid:2.1.1' implementation 'io.reactivex.rxjava2:rxjava:2.2.17' implementation 'io.reactivex.rxjava2:rxkotlin:2.4.0' implementation 'com.jakewharton.rxbinding3:rxbinding:3.1.0' implementation 'com.uniquext.android:rxlifecycle:2.0.0' 이전 1 2 3 다음