How can I use the value of a variable as constant?

Question

1. I have a PHP site which uses language system based on \"define\" method. For example:

   define(\"_question_1\", \"How old are you?\");
   define(\"_quest         
   
   
           

Answer 1

Try constant() it returns the value of a constant, for example:

var_dump(constant('YourConstantNameHere'));

or with variables

var_dump(constant($a));

http://www.php.net/manual/en/function.constant.php

Answer 2

Just use constant() to use your variable value as constant, e.g.

echo constant($a);

Answer 3

1. In PHP you could use variable variable – dynamic variable names.

   $a = '_question_3'; 
   $b = 'Question 3?';
   
   $$a = $b;
   echo $b;
   // prints "Question 3?"
   echo $_question_3;
   // prints "Question 3?"
   

But it's not good solution. Try not to use dynamic variable names.

2. May be associative array will be more suitable to you?

   $questions = []; // Creating an empty array
   $questions['_question_3']['question'] = 'Question 3?'; // Storing a question
   $questions['_question_3']['answers'] = [ // Adding answers
       'Answer 1',
       'Answer 2',
       'Answer 3'
   ];
   

3. Or declare a Question class and create instances of it.

   class Question
   {
     public $Question;
   
     public $Answers;
   
     __construct($question, $answers)
     {
        $this->Question = $question;
        $this->Answers = $answers;
     }
   }
   
   $q1 = new Question('Question 1?', ['Answer 1', 'Answer 2', 'Answer 3']);