Tuesday, February 25, 2020

android kotlin - String replace range example

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 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"
    tools:context=".MainActivity">
    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="8dp"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:textColor="#5218FA"
        android:textStyle="normal"
        android:textSize="24sp"
        android:fontFamily="sans-serif-condensed"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
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