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Simple RecyclerView example with filter option in Android

Hi Guys, Maybe you all are expert in terms of using RecyclerView in android. This blog is simple example for using filter option with RecyclerView adapter. As for now you will instantiate RecyclerView and set the adapter to RecyclerView as following way. RecyclerView list = (RecyclerView) findViewById(R.id.list); list.setLayoutManager(new LinearLayoutManager(this)); list.setHasFixedSize(true); ArrayList&ltNumber&gt numbers = new ArrayList&lt&gt(); String ONEs[] = {"ZERO", "ONE", "TWO", "THREE", "FOUR", "FIVE", "SIX", "SEVEN", "EIGHT", "NINE", "TEN"}; String TENs[] = {"ZERO", "TEN", "TWENTY", "THIRTY", "FOURTY", "FIFTY", "SIXTY", "SEVENTY", "EIGHTY", "NINETY", "HUNDRED"}; String HUNDREDS[] = {"ZERO", "HUNDRED", "TWO HUND

Basic data types of KOTLIN and simple examples.

In this section we describe the basic types used in Kotlin: numbers, characters, booleans, arrays, and strings.

Numbers

Kotlin handles numbers in a way close to Java, but not exactly the same. For example, there are no implicit widening conversions for numbers, and literals are slightly different in some cases.

Kotlin provides the following built-in types representing numbers (this is close to Java):

Type Bit width
Double 64
Float 32
Long 64
Int 32
Short 16
Byte 8


We can declare data types in KOTLIN as following way.
var a: Int = 0 //int var, we can reassign at runtime or anywhere in the code. 
val a:Int =0 //int val, val cannot reassign.
var a = 0 //int var
val a = 0 //int val

var a = 10.10 //Double
var a = 10.10f //Float
var a = 10.10F //Float

var a = 10L //Long

//You can use underscores to make number constants more readable:
val oneMillion=1_000_000

Every number type supports the following conversions:

toByte(): Byte

toShort(): Short

toInt(): Int

toLong(): Long

toFloat(): Float

toDouble(): Double

toChar(): Char

Operations


Here is the complete list of bitwise operations (available for Int and Long only):
  1. shl(bits) – signed shift left (Java's <<)
  2. shr(bits) – signed shift right (Java's >>)
  3. ushr(bits) – unsigned shift right (Java's >>>)
  4. and(bits) – bitwise and
  5. or(bits) – bitwise or
  6. xor(bits) – bitwise xor
  7. inv() – bitwise inversion

Ex:

var x = 1 shl 2
var x = 1 shr 2
var x = 1 ushr 2
var x = 1 and 2
var x = 1 or 2
var x = 1 xor 2
var x = 1.inv()

Also we have int() instead of ++ and dec() instead of --.

Ex:

var x = a.inc()

Characters

Characters are represented by the type Char
var c = 'a'.

Booleans

The type Boolean represents booleans, and has two values: true and false.
var b = true

Strings

Strings are represented by the type String. Strings are immutable. var s = "Hello Kotlin"

Interesting right?


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