Keeping track of 2 key array

Question

I'm trying to implement a polling system where if the user lands on a particular poll page and actually answers the question, then the id and their option will be logged. For example, let's say the id of that question is 67 and they answered option 2, then I want the array to look something like this: 67:2. The log array data will be kept in a SESSION variable, and each time the user answers a question it'll add on to this array. When the user tries to navigate to a poll he/she answered already, then it'll display the answered option.

I know I could use concatenate and the in_array function if this was an array of only numbers, like "3,2,1,5,6" but how can I do this for this type of array? ("3:1, 2:2, 1:1") where the first digit is the id and the second digit is the option chosen. How do I use if (in_array($id)) when after concatenation it'll be something like this "3:1"?

I am unable to create a fiddle because of `$_SESSION` usage. — Praveen Kumar Purushothaman, Dec 31 '16 at 23:46
It's perfectly clear, not sure why someone has voted to close it as unclear. — Praveen Kumar Purushothaman, Dec 31 '16 at 23:52
You may want to take a look at serialize() function http://stackoverflow.com/questions/1180602/what-is-phps-serialize-function-for - seems potentially useful to you, perhaps insure you are familiar with the difference between an indexed and associative array in php – good luck. — luckyape, Dec 31 '16 at 23:52
@luckyape I believe associative array is good for this use case, right? — Praveen Kumar Purushothaman, Dec 31 '16 at 23:54
@PraveenKumar i agree – i mentioned it only because the question referenced integers as array keys. Your answer wisely replaces the integers with stings. — luckyape, Dec 31 '16 at 23:59

score 3 · Accepted Answer · answered Dec 31 '16 at 23:40

I would say, you can do this way:

// Log an answer:
$_SESSION["polls"][$question] = $answer;

This way, it will be logging:

{
  "polls": {
    "question-6": "answer-2",
    "question-4": "answer-1"
  }
}

So there will be no duplication. To check if the user has answered already, you can do this:

in_array("question-6", array_keys($_SESSION["polls"]))

This will give you if the user has answered question 6 or not.

PHP Script

<?php
    header("Content-type: text/plain"); session_start();
    // Log few questions and answers.
    $question = "question-67";
    $answer = "answer-2";
    $_SESSION["polls"][$question] = $answer;
    $question = "question-55";
    $answer = "answer-1";
    $_SESSION["polls"][$question] = $answer;
    $question = "question-42";
    $answer = "answer-3";
    $_SESSION["polls"][$question] = $answer;
    // Let's check if the next question, which will be the same one, has been answered or not.
    $question = "question-67";
    $answer = "answer-2";
    if (in_array($question, array_keys($_SESSION["polls"])))
        echo "Question has been answered.";
    else
        echo "Question not answered.";
?>

I get the output as:

Question has been answered.

If the question has already been answered, how can I get the user's answer to that question from the session variable? — user2896120, Dec 31 '16 at 23:47
@user2896120 This gives the answer: `$_SESSION["polls"][$question]` will have the answer for the `$question`. — Praveen Kumar Purushothaman, Dec 31 '16 at 23:48
@user2896120 When I change the line: `echo "Question has been answered.";` to `echo "Question has been answered. The answer is: {$_SESSION["polls"][$question]}";`, it will display me: `Question has been answered. The answer is: answer-2`. Happy? — Praveen Kumar Purushothaman, Dec 31 '16 at 23:50

Keeping track of 2 key array

1 Answers1