变量没有“坚持”到数组

I'm using twilio to send SMS's. If I insert my number directly 8881231234 it will work. This code below works:

$client = new Services_Twilio($sid, $token);
$message = $client->account->messages->sendMessage(
  '9991231234', // From a valid Twilio number
  '8881231234', // Text this number
  "Hello monkey!" //insert message here
);

print $message->sid;

but when I replace by adding record from database it wont work. Like below it wont work:

echo $row2["handset"]; // I can see my number

$client = new Services_Twilio($sid, $token);
$message = $client->account->messages->sendMessage(
  '9991231234', // From a valid Twilio number
  '$row2["handset"]', // Text this number
  "Hello monkey!"
);

print $message->sid;

I echo $row2["handset"] and my numbers 8881231234 appear correctly. This also didn't work:

$handset = '8881231234';

$client = new Services_Twilio($sid, $token);
$message = $client->account->messages->sendMessage(
  '9991231234', // From a valid Twilio number
  '$handset', // Text this number
  "Hello monkey!" // insert message here
);

print $message->sid;

Why is that? Help me please.

If you want a variable be interpreted as a variable, use double quote:

$var = "$var2";

$var = '$var2'; does not work as excepted.

It works with array too:

$var = "$var2['whatever']";

Or simply do:

$var = $var2['whatever'];

With concatenation:

$var = $var2['whatever']."suffix";

Well in your case you only want to do:

$message = $client->account->messages->sendMessage(
  '9991231234', // From a valid Twilio number
  $row2["handset"], // Text this number
  "Hello monkey!"
);