如何在PHP Heredoc中转义变量名？

I have a variable $foo with some id in it and I want to use it in Heredoc string in PHP like this:

$text = <<<TEXT
  <div id="$foo_bar"></div>
TEXT;

Obvious problem is that PHP parses variable in Heredoc as $foo_bar which of course, doesn't exist. What I want is to parse $foo variable and "_bar" should be treated as regular text.

Is it possible to use some kind of escape character or it can't be achieved ?

P.S.: Yes, I know I can use quoted string instead of Heredoc, but I must use Heredoc (I have a ton of text and code in it with quotes, etc).

Put curly braces around the variable, just like in a quoted string.

$text = <<<TEXT
  <div id="{$foo}_bar"></div>
TEXT;

Use this code instead to force using $foo.

$text = <<<TEXT
  <div id="{$foo}_bar"></div>
TEXT;

Curly brackets force the contents to be a variable.

Alternatively, you could attach "_bar" before the HEREDOC.

$foo = $foo . "_bar";
$text = <<<TEXT
  <div id="$foo"></div>
TEXT;