Sunday, February 23, 2020

android kotlin - String isBlank and isEmpty 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 = "     "

        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().toString())

        // Returns true if this char sequence is
        // empty (contains no characters).
        textView.append("\n\nString is empty? ")
        textView.append(string.isEmpty().toString())
    }
}
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="8dp"
        android:layout_marginEnd="8dp"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:textColor="#5F9EA0"
        android:textStyle="normal"
        android:textSize="30sp"
        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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