PHP - Variable inside variable?

Question

Hey guys...

$bookA = "123";
$crack = "A";

I want to do something similar to this:

echo $book$crack;

Such that the output is 123.

What is the correct syntax for the echo command?

Thanks.

Answer 1

$varname = 'book'.$crack;
echo $$varname;

Answer 2

These are called variable variables, but you should use arrays instead.

Answer 3

echo ${"book" . $crack};

Answer 4

This will work:

$bookA = "123";
$crack = "A";
$var = "book$crack";
echo $var;

Answer 5

You might want to use an associative array.

For instance:

$book = array();
$book["A"] = "Some Book";
$crack = "A";

//Later
echo $book[$crack];