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android kotlin - String replace range example

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
        // in the part to be replaced.
        val result = string.replaceRange(
            25..100, // range
            " replaced string " // replacement
        )

        textView.append("\n\n\n")
        textView.append("Replace range (25..100) with " +
                "( replaced string )...\n\n")
        textView.append(result)


        /*
            documentation source kotlinlang.org
                Replaces the part of the string at the given
                range with the replacement char sequence.

                startIndex - the index of the first character to be replaced.
                endIndex - the index of the first character after
                           the replacement to keep in the string.
        */
        val result2 = string.replaceRange(
            40, // start index
            125, // end index
            " new string " // replacement
        )

        textView.append("\n\n\n")
        textView.append("Replace (start index 40 end index" +
                " 125) with ( new string )...\n\n")
        textView.append(result2)
    }
}
activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#F8F8F8"
    android:padding="24dp">

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:fontFamily="sans-serif"
        android:textSize="20sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
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