PHP Getting a variable by name and concatention

Question

I am having this problem getting a variable by its name. What I am doing is including a path with connections and I want the connections are named in a certain way. I want to iterate through those conenctions and add them to a queue but the problem is, I cannot use '.' to concat a variable.

Code looks like this. Config File:

//Set the host the databse will connect too
    $config_db_hostname='xxx.xxx.xxx';
    //Set the user who is connecting to the database
    $config_db_user='a user';
    //Set the password for user who is connecting to the database
    $config_db_pass='abc123';
    //Set the database type
    $config_db_type='mysql';
    //Set the name of the database
    $config_db_name='phonephare_development';
    //Optional: Set the schema, if any
    $config_db_schema='';
    //Optional: Set the port, otherwise default port will be used
    $config_db_port='';
    //Set the prefix for the table names
    $config_db_prefix='pf_';

    //Set the host the databse will connect too
    $config_db_hostname_1='localhost';
    //Set the user who is connecting to the database
    $config_db_user_1='test';
    //Set the password for user who is connecting to the database
    $config_db_pass_1='test';
    //Set the database type
    $config_db_type_1='mysql';
    //Set the name of the database
    $config_db_name_1='test_development';
    //Optional: Set the schema, if any
    $config_db_schema_1='';
    //Optional: Set the port, otherwise default port will be used
    $config_db_port_1='';
    //Set the prefix for the table names
    $config_db_prefix_1='pv_';

Function for getting values:

public static function init(){
        if(file_exists(PV_DB_CONFIG)){
            include(PV_DB_CONFIG);


            for ($i = 0; $i <= 3; $i++) {
                if($i){
                    $profile_id='_'.$i;
                } else {
                    $profile_id='';
                }
                // Database variables
                self::$connections['connection'.$profile_id]['dbhost'] = ($config_db_hostname.$profile_id);
                self::$connections['connection'.$profile_id]['dbuser'] = $config_db_user.$profile_id;
                self::$connections['connection'.$profile_id]['dbpass'] = $config_db_pass.$profile_id;
                self::$connections['connection'.$profile_id]['dbtype'] = $config_db_type.$profile_id;
                self::$connections['connection'.$profile_id]['dbname'] = $config_db_name.$profile_id;
                self::$connections['connection'.$profile_id]['dbport'] = $config_db_port.$profile_id;
                self::$connections['connection_'.$profile_id]['dbschema'] = $config_db_schema.$profile_id;
                self::$connections['connection_'.$profile_id]['dbprefix'] = $config_db_prefix.$profile_id;
            }

        }

}//end init

So how can I dynamically read this variables?

Man, stop doing this. Use arrays instead!

GolezTrol
– GolezTrol

2011-09-30 13:46:38 +00:00
Commented Sep 30, 2011 at 13:46 — GolezTrol
– GolezTrol, Commented Sep 30, 2011 at 13:46

GolezTrol · Accepted Answer · 2011-09-30 13:50:29Z

4

You can read 'dynamic' variables like this:

$varname = 'config_db_user';
if ($i)
  $varname .= '_' . $i;

$varvalue = $$varname; // $varvalue contains the value now.

But this will make your code really hard to read and hard to maintain. Rather make your config like this:

$profiles[1]['config_db_user'] = 'whatever';

Then, you can just read $profiles[$profile_id]['configfield] to get what you want. There are probably other ways that may even be better, but stop putting together dynamic variable names, because that's the worst of all.

answered Sep 30, 2011 at 13:50

GolezTrol

116k19 gold badges186 silver badges215 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Karoly Horvath · Accepted Answer · 2011-09-30 13:47:30Z

2

Check PHP variable variables.

Note: that's a bad config file format to start with, you really should put the separate connections to different arrays. Check the config file of phpmyadmin.

answered Sep 30, 2011 at 13:47

Karoly Horvath

96.7k11 gold badges123 silver badges181 bronze badges

Comments

N.B. · Accepted Answer · 2011-09-30 13:47:17Z

1

Construct your data in a different way. You want to iterate trough group of variables that share a similar name.. yet, it didn't occur to you to use an array for config options and iterate trough that?

answered Sep 30, 2011 at 13:47

N.B.

14.1k3 gold badges47 silver badges56 bronze badges

Collectives™ on Stack Overflow

PHP Getting a variable by name and concatention

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related