Android Question Check if whatsapp if installed so it can be used with intent

Public void onClickWhatsApp(View View) {

    Intent waIntent = new Intent(Intent.ACTION_SEND);
    waIntent.setType("text/plain");
            String text = "YOUR TEXT HERE";
    waIntent.setPackage("com.whatsapp");
    If (waIntent != Null) {
        waIntent.putExtra(Intent.EXTRA_TEXT, text);//
        StartActivity(Intent.createChooser(waIntent, "Share with"));
    } Else {
      Toast.makeText(this, "WhatsApp not Installed", Toast.LENGTH_SHORT)
                .show();
    }

}

Sub Share_word_pass
  Dim tx As String
  Dim Intent1 As Intent
  tx = "TEST"
 
  Intent1.Initialize(Intent1.ACTION_SEND ,"")
  Intent1.SetType("text/plain")
  Intent1.SetComponent("com.whatsapp")
   
  If Intent1 <> Null Then   ' I don't think this is right
    Intent1.SetComponent("com.whatsapp/.ContactPicker") 'ContactPicker
    Intent1.PutExtra("android.intent.extra.TEXT",tx)
    StartActivity(Intent1)
  End If
End Sub