Monday, February 24, 2020

android kotlin - String remove 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."

        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 // range
        )


        textView.append("\n\n\n")
        textView.append("After removing range (10..50)....\n")
        textView.append(result)

        /*
            documentation source kotlinlang.org
                Removes the part of a string at a given range.
                startIndex - the index of the first character to be removed.
                endIndex - the index of the first character after
                           the removed part to keep in the string.
                endIndex is not included in the removed part.
        */

        val result2 = result.removeRange(
            5, // start index
            25 // end index
        )

        textView.append("\n\n\n")
        textView.append("Removing from result" +
                " (start index 5, end index 25)....\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="#2A52BE"
        android:textStyle="normal"
        android:textSize="27sp"
        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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