![Lists: Mutable Vs Immutable:
Lists: A linear data structure used to store data.
Syntax:
<Keyword> <variable name>:List<Data type of item> = listOf(<i1>,<i2>,<i3>,....)
Usage: (Immutable Lists)
val list1:List<Int> = listOf(1,2,3,4,5,6)
val list2:List<String> = listOf(“a”,”b”,”c”)
Methods/Functions: (More: https://kotlinlang.org/docs/list-operations.html)
.size -> Int
l1[index]
l1.first()
l1.last()
l1.indexOf(element)
l1.subList(0,3)
l1.reversed() -> List
l1.contains(element) -> Boolean
l1.sorted() -> List](https://image.slidesharecdn.com/session2androidstudyjam-211224110219/85/Session-2-android-study-jam-4-320.jpg)
Session 2 android study jam
- 1. Hold On. It will start soon :)
- 2. Become an Android Developer Session - 2: Layouts, Views and Project Demo 24/12/2021 12:00 PM - 1:00PM IST GDSC DYPIU Host: Atharv Karbhari
- 3. Topics: ● Lists : Mutable vs Immutable ● Conditional Statements ● Project Demo: Simple Button App ● with and when Keywords ● Views and Binding ● Project Demo: Tip Calculator App ● Useful functions
- 4. Lists: Mutable Vs Immutable: Lists: A linear data structure used to store data. Syntax: <Keyword> <variable name>:List<Data type of item> = listOf(<i1>,<i2>,<i3>,....) Usage: (Immutable Lists) val list1:List<Int> = listOf(1,2,3,4,5,6) val list2:List<String> = listOf(“a”,”b”,”c”) Methods/Functions: (More: https://kotlinlang.org/docs/list-operations.html) .size -> Int l1[index] l1.first() l1.last() l1.indexOf(element) l1.subList(0,3) l1.reversed() -> List l1.contains(element) -> Boolean l1.sorted() -> List
- 5. Lists: Mutable Vs Immutable: Lists: A linear data structure used to store data. Syntax: <Keyword> <variable name>:MutableList<Data type of item> = mutableListOf(<i1>,<i2>,<i3>,....) Usage: (Mutable Lists) val l1:MutableList<Int> = mutableListOf(1,2,3,4) Methods/Functions: (More: https://kotlinlang.org/docs/list-operations.html) l1.size -> Int l1.first() l1.last() l1.addAll() l1.add(3) -> Boolean (false if could not add) l1.remove(3) -> Boolean (false if doesn’t exist) l1.reversed() l1.contains(3) l1.sorted() l1.removeAt(2) l1.isEmpty() -> Boolean l1.clear()
- 7. “with” vs “when” Usage: with (object){ property1 // Equivalent of object.property1 property2 // Equivalent of object.property2 print(property3) // print(object.property3) }
- 8. “with” vs “when” Usage: 1. when (object){ value1 -> <statement 1> value2 -> <statement 2> value3 -> <statement 3> value4 -> <statement 4> } 2. val obj1 = value when { value1 > 10 -> <statement 1> value2 == 5 -> <statement 2> value3 <= 5 -> <statement 3> value4 + 1 ==10 -> <statement 4> }
- 9. Project Demo - 1 Button App Layout Design Integrate XML Adding Vector and Image Assets
- 10. Layout(Padding Vs Margin) Padding Margin 1. Padding: Distance between View content and View Body 2. Margin: Distance between View Body and Parent View
- 11. Project Demo - 2 Tip Calculator
- 12. View Binding Vs findViewById() App/build.gradle: buildFeatures { viewBinding true } MainActivity.kt: private lateinit var binding: ActivityMainBinding override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) binding = ActivityMainBinding.inflate(layoutInflater) setContentView(binding.root) } Usage: binding.view1 // same as findViewById<View>(R.id.view1) binding.view2 // same as findViewById<View>(R.id.view2)
- 13. View Binding Vs findViewById() Cheatsheet / Summary: View Binding: One reference to all views having id findViewById(): Add a reference to a view Important Tags: android:text="This text" android:layout_below="@+id/another_view" android:padding="40dp" android:layout_margin="40dp" android:layout_centerVertical="true" android:layout_centerHorizontal="true" wrap_content: Match height/width according to content match_parent: Match height/width/property of parent view
- 14. Thank You!! Host: Atharv Karbhari LinkedIn Github Hackerrank