Unresolved reference: launch. I can't write example with kotlin coroutines

Question

I am going to learn kotlin coroutines, but i got problem on android studio.

I did need imports of library in gradle, but I got problems with code compiler.

I just can't use launch. Kotlin version is 1.3.50. Error: Unresolved Reference Launch

Import

import kotlinx.coroutines.delay
import kotlinx.coroutines.*

Code which I try to use:

suspend fun firstCoroutine(){
        println("Kotlin Start")
        launch(CommonPool){
            delay(2000)
            println("Kotlin Inside")

        }
        println("Kotlin End")
    }

My build.gradle app file

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

apply plugin: 'kotlin-kapt'
//эти файлы используюстя для компиляции, построения и упаковки приложений и библиотек
//настройки для модуля
android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "guard_studio.akira.firstcotlinproject"//идентификатор приложения
        minSdkVersion 17//минимальная поддерживаемая версия сдк
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"//версия приложения для гугл плэй
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

//список библиотек подключенных к проекту
dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    //coroutines
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.2'
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.2"
}

build.gradle level project

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
        
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven {
            url "http://dl.bintray.com/kotlin/kotlin-eap"
        }
    }

}

Answer 1

It seems that you are following an outdated tutorial. You have to use CoroutineScope if you want to use latest version of the coroutines. Just for start you can use GlobalScope:

import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

suspend fun firstCoroutine() {
    println("Kotlin Start")
    GlobalScope.launch {
        delay(2000)
        println("Kotlin Inside")

    }
    println("Kotlin End")
}