如何检查作为数组元素存储的名称是否作为独立数组本身存在

Question

Suppose I have the following arrays:

$table_names = array('foo', 'bar');

And I have some other arrays:

$foo = array('1', '2', '3');

$bar = array('4', '5', '6');

I want to check if the names stored in $table_names exist as independent arrays. For example:

foreach($table_names as $names) {

    // Check if array exists with name $names

}

Can anyone please tell me if it's possible?

I'm basically exporting my database in PHP array format. I upload the file using the script and then I want to use those arrays in my code so I can show particular information on screen without having to add data into database.

Thank you in advance! Cheers

Answer 1

Yes this is is possible through the use of variable variables.

foreach($table_names as $n) {
    if(isset($$n) && is_array($$n)) {
        print_r($$n);
    }
}

Example

---

Basically variable variables are used like this:

$VARIABLENAME

Since we loop through $table_names as a 1D array, you can check $$n to see if it exists and is an array, if so, print_r() it.

Note: The manual shows this warning:

Please note that variable variables cannot be used with PHP's Superglobal arrays within functions or class methods. The variable $this is also a special variable that cannot be referenced dynamically.