Q:

Retrieving string for if/else clause in android studio

I'm trying to get a qr code scanner going where it should redirect to different activities in dependancy on the code scanned but I'm having trouble getting the string from the result in the correct form.
  @Override
public void handleResult(Result result) {
    Log.w("handleResult", result.getText());
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Scan results");
    builder.setMessage(result.getText());
    AlertDialog alertDialog = builder.create();
    alertDialog.show();

    String id_helper = result.getText().toString();

    if (id_helper == "1") {
       startActivity(new Intent(this, Sample1.class));
    } else if (id_helper == "2") {
        startActivity(new Intent(this, Sample2.class));
    } else {
        startActivity(new Intent(this, Sample3.class));
    }

A:

You are comparing the string in wrong way, In Java you have to compare string using the equals method.
if ("1".equals(id_helper)) {
    // Open activity
}

Always put the known variable as on the left side of the condition to avoid NullPoinerExceptions.

