PHP doesn't render entire "echo".

[A_6]

The code is:
echo " AS " . $index - 10 . " - " . $index . " SA ";

$index is an integer.

The output is:
-10 - 0 SA

The expected output is:
AS -10 - 0 SA

What am I missing?

[rproffitt]

Try this instead.
echo " AS ", $index - 10 . " - " . $index . " SA ";

[A_6]

Yea well that works. But why does it happen? Is my syntax incorrect? Is there a rule you can't put words before mathematic operation?

[rproffitt]

I defer to http://php.net/manual/en/language.operators.precedence.php as you did ask it to concatenate " AS " to $index.
Sorry if you feel shortchanged here. It's one of those questions that pop up a lot.

[cereal]

In addition, you can also do:

echo " AS " . ($index - 10) . " - " . $index . " SA ";