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how to run cloned/github remote react native app, err msg no android

NOTES: Im new in react native and i see there are so many approaches and with this error i thought the developer who built this app build it differently from what i learn so i don't understand why he didn't put the android folder
so i just joined a project and im going to run the apps in my pc by cloning it from github but when i try to npx react-native run-android it failed to run and the log is like this
error Android project not found. Are you sure this is a React Native project?
If your Android files are located in a non-standard location (e.g. not inside 'android' folder),
consider setting project.android.sourceDir option to point to a new location.
info Run CLI with --verbose flag for more details.
the folder structure is like this

The files show that the project is created with Expo. Specifically, you have a managed expo project.
npx react-native run-android would compile an android app from source, with Expo's managed workflow that's not needed. You will need the Expo Go App.
Expo also comes with its own commands to start the bundler. Instead of running npx react-native ... make use of the expo-cli running: npx expo start
However, in the package.json there is very likely a script called start. In that case, it's easier for you to run npm start.
After running this command the expo console opens. Here you can press a to open the app using expo go (or instructions on how to do so).
Alternatively, you can run npx expo run:android to start the expo go app on android yourself.

you are using an expo, there is a folder named .expo-shared, after
npm install
Try to run
npm start
or
expo start
or
npx expo start
something like this will appear:
https://imgur.com/U9I7Gf4
after that go to the terminal, open the emulator in you computer and click on the terminal and press 'a',

React Native Windows App Loading Error (80072f78)

I'm new to react and react-native, and am attempting to run the react-native-windows template project but have encountered an issue.
Error
App loads in a blank window with error banner Error 80072f78 downloading http://localhost:8081/index.bundle?platform=windows&dev=true&hot=false&inlineSourceMap=true
Image for reference
What I've Tried
I followed the instructions on the react-native-windows getting started docs
Namely:
npx react-native init <projectName> --template react-native#^0.63.2
cd projectName
npx react-native-windows-init --overwrite
npx react-native run-windows
The process will start another terminal window with the react logo. The application will build successfully, and will start in a new window. However, the original error is always present.
I've tried uninstalling and reinstalling all relevant programs. I've also tried building in both c# and c++, to no avail (adding the --language flag in the third step above).
Versions
react-native-windows: 0.63
react-native: 0.63.2
Windows SDK: 10.0.18362.0
node: 14.16.0
npm: 6.14.11
I couldn't find any issues like this online. If anyone has a suggestion, I would appreciate it. I'm more than happy to provide further info. Thanks!

New project with react native but errors

My head is so pain right now, I just screw up my old project and not able to run currently, So I guess I just create a new react native project and transfer my code to it, guess what? I hit this error after my creation of react native and ran react-native run-android.
:app:compileDebugSources UP-TO-DATE
:app:transformClassesWithDexForDebug
Running dex in-process requires build tools 23.0.2.
For faster builds update this project to use the latest build tools.
:app:transformClassesWithDexForDebug FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:transformClassesWithDexForDebug'.
> com.android.build.api.transform.TransformException: java.lang.RuntimeException: java.lang.RuntimeException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: java.lang.IllegalStateException: dx.jar is missing
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
Total time: 4.998 secs
Could not install the app on the device, read the error above for details.
Make sure you have an Android emulator running or a device connected and have
set up your Android development environment:
https://facebook.github.io/react-native/docs/getting-started.html
This multidex thing, I never set this before or anything previously on my 1st project like 1 week ago. With a new project, I can't even run my android emulator with react-native run-android for the 1st time.
Someone please help me to solve this issue please.

There are some common solutions for this issue. First of all you need to find your buildToolsVersion in gradle file.
To import react native project into android studio follow these steps.
Open Android Studio and click Open existing project
Find your project folder and inside that there will be folder called android
Open that folder with android studio
Make sure you have the newest android studio release.
If there is any build error just fix them simply by clicking the errors.
Once you have correctly build your project find build.gradle (Module:app) file under Gradle Scripts.
There you can see the buildToolsVersion of your current project. Change it like this
android {
compileSdkVersion 23
buildToolsVersion "23.0.3"
After that clean your android project using Build > Clean Project
Next rebuild your android project using Build > Rebuild Project
After that navigate your react native project folder and delete build folder.
It can be found here YourProject > android > app > build
Then before you run your react native project, note that Android Emulator is already running. If not run your android emulator using android studio
Finally run your react native project using react-native run-android

I can't run my react native code even though I have an emulator running in the back round

I am trying to run react native code but when I use react-native run-android I get this error message. I am using android studio.
~/Downloads/BrainG-master$ sudo react-native run-android
Scanning folders for symlinks in /home/luke/Downloads/BrainG-
master/node_modules (10ms)
JS server already running.
Building and installing the app on the device (cd android && ./gradlew
installDebug)...
: No such file or directory
Could not install the app on the device, read the error above for
details.
Make sure you have an Android emulator running or a device connected
and have
set up your Android development environment:

Make sure
there is an android directory inside /Downloads/BrainG-master (I hope you're not running react-native run-android from within the android directory) and
your local.properties file in BrainG-master/android has the location of your android SDK specified in the following format: sdk.dir=/Users/username/pathToYourAndroidSdk.
If there is no local.properties file, open the project in Android Studio and it will create that for you.
If you're on Linux, you can also configure the android home environment thus:
Add the following lines to your $HOME/.bash_profile config file:
export ANDROID_HOME=$HOME/Android/Sdk
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/platform-tools
.bash_profile is specific to bash. If you're using another shell, you will need to edit the appropriate shell-specific config file.
Type source $HOME/.bash_profile to load the config into your current shell. Verify that ANDROID_HOME has been added to your path by running echo $PATH.
You can follow the instructions here: https://facebook.github.io/react-native/docs/getting-started.html#2-install-the-android-sdk

JS and React Native: node.js doesn't accept 'import' keyword

I'm a beginner in using JavaScript and the framework React Native.
I have the task to program a mobile web app with React Native with another student from my class. He started to build an app, which is build without any problems on his Android Emulator. He sent me his App and node.js (my editor is JetBrains WebStorm, my partner uses the same editor) does not recognize my import react.
But when I start the app in my command line with react-native run-android everything function and I can see the app, but my problem is
that I can't run it from my editor.
I have already install those in my command line:
C:\Users\Hang>npm install -g yarn
C:\Users\Hang>npm install -g react-native-cli
What did I forget to install ?
Here is a screenshot of the message that I get when I try to run the App:

You are using Node.js Run configuration to start your application, but Node.js doesn't support ES6 modules natively (thus the Syntax erroron import), and, of course, it doesn't support react-native cli options, so running node index.android.js as you do won't start your app in android emulator. You should have used React Native run configuration instead. Please see https://blog.jetbrains.com/webstorm/2016/12/developing-mobile-apps-with-react-native-in-webstorm/, Running and debugging the app section

You have to install the react Native CLI for your IDE (webstorm)
you will find It here