Programming Tutorials

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry." textView.text = string // Returns a substring of this string that starts at the // specified startIndex and continues to the end of the string. val result = string.substring( 50 // ...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry. Lorem Ipsum" + " has been the industry's standard dummy text" + " ever since the 1500s." textView.text = string // The end index of the range is included ...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry. Lorem Ipsum" + " has been the industry's standard dummy text" + " ever since the 1500s." textView.text = string /* documentation source kotlin...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry. Lorem Ipsum" textView.text = string /* documentation source kotlinlang.org Removes the given delimiter string from both the start and the end of this string if and o...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry." textView.text = string // Removes the part of a string at the given range. // The end index of the range is included in the removed part. val result = string.removeRange( 10..50 //...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string1 = "This is a sample string to" + " test remove prefix function." textView.text = string1 /* documentation source kotlinlang.org If this string starts with the given prefix, returns a copy of this string with the prefix removed. Otherwise, ret...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string1 = "This is a sample string to test the function." val string2 = "This is another SAMPLE string to test the " + "string region matches method." textView.text = string1 textView.append("\n\n") textView.append(string2) /* documentation so...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and \ntypesetting industry. Lorem Ipsum" + " has been the industry's \nstandard dummy text" + " ever since the 1500s, when \nan unknown printer" + " took a galley of type and \...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "This is A SAMple striNg." textView.text = string /* documentation source: kotlinlang.org Splits the original char sequence into pair of char sequences, where first char sequence contains characters for which predicate yielded true, while second char sequen...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry." textView.text = string // string is returned as is, when its // length is greater than the specified val afterPadStart10 = string.padStart(10,'*') textView.append("\n\nAfte...

MainActivity.kt package com.example.jetpack import android.os.Bundle import androidx.appcompat.app.AppCompatActivity import kotlinx.android.synthetic.main.activity_main.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) val string = "Lorem Ipsum is simply dummy text \nof the" + " printing and typesetting industry. Lorem" + " Ipsum has been the industry's \nstandard dummy" + " text ever since \nthe 1500s, when an unknown" + " printer took a galley of type \nand scrambled" + " it to make a type specimen book." textView.text = string /* source: kotlinlang.org Splits this char sequence to a list of lines delimited by any of the following...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = " " textView.text = "This string ($string)" + " length is " + string.length // Returns true if this string is empty // or consists solely of whitespace characters. textView.append("\n\nString is blank? ") textView.append(string.isBlank().toStr...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the printing" + " and typesetting industry. Lorem Ipsum has been the" + " industry's standard dummy text ever since the 1500s," + " when an unknown printer took a galley of type" + " and scramble...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string1 = "This is a sample string." val string2 = "This is a SAMPLE string." textView.text = "String 1 : \n$string1" textView.append("\n\nString 2 : \n$string2") // Compares two strings lexicographically, // optionally ignoring case differences. if (string1.com...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the printing" + " and typesetting industry. Lorem Ipsum has been the" + " industry's standard dummy text ever since the" + " 1500s, when an unknown printer took a galley" + " of type and scramble...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity import java.util.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "this is a sample string." textView.text = string textView.append("\n\nAfter capitalize it....") // Returns a copy of this string // having its first letter uppercase. textView.append("\n" + string.replaceFirstChar { if (it.isLowerCase()) it.t...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity import java.util.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "Lorem Ipsum is simply dummy text of the" + " printing and typesetting industry." textView.text = string // Splits this char sequence into a list // of strings each not exceeding the given size. val list:List<String> = string.chunked(15) //...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() val string = "This is Android SDK 33" textView.text = string // Returns true if all characters match the given predicate. val result:Boolean = string.all{ it.isDigit() } textView.append("\n\nIs this string contain only digit? $result") // Returns true if at least one chara...

MainActivity.kt package com.cfsuman.kotlintutorials import android.os.Bundle import android.text.method.ScrollingMovementMethod import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) // get the widgets reference from XML layout val textView = findViewById<TextView>(R.id.textView) // make textview content scrollable textView.movementMethod = ScrollingMovementMethod() // drop example val string = "This is a sample string." // Returns a string with the first n characters removed. val result = string.drop(5) textView.text = string textView.append("\nAfter dropping 5 chars") textView.append("\n$result") // drop last example val ...

Iterating Over Strings in Android with Kotlin This code demonstrates two ways to iterate over the characters in a string within an Android application written in Kotlin. The application presents two buttons: "Iterate over string": Clicking this button iterates through the characters of a string variable without using an index property. "Iterate string using index": Clicking this button iterates through the characters using the string's index property. Both button clicks update a TextView element, displaying the characters of the string one by one on separate lines. Breakdown and Functionality The code consists of two main parts: the MainActivity.kt file containing the Kotlin code and the activity_main.xml file defining the user interface layout. MainActivity.kt: Imports: The code imports necessary libraries for building the user interface and working with resources. Class Definition: The MainActivity class inherits from AppCompatActivity , which i...