How do I use a variable to build an array name?

Question

I have several sets of arrays. Each set begins with the same word:

var firstarrayquestions = ["", "", ""];
var firstarrayanswer1 = ["", "", ""];
var firstarrayanswer2 = ["", "", ""];

var secondarrayquestions = ["", "", ""];
var secondarrayanswer1 = ["", "", ""];
var secondarrayanswer2 = ["", "", ""];

(...etc...)

This may be a question with an obvious solution, but if I want to have one function that handles displaying questions and answers from each array, how would I code that? Something like this:

function handleQuestion(myStr) {
    var randomstart = 0; //just for example
    $('#question').text(myStr + arrayquestions[randomstart]);
    $('#q1').text(myStr + arrayanswer1[randomstart]);
    $('#q2').text(myStr + arrayanswer2[randomstart]);
}

handleQuestion('first');

Many thanks!

adeneo · Accepted Answer · 2014-01-08 18:05:29Z

You could use bracket notation if you know the scope, something like

function handleQuestion(myStr) {
    var randomstart = 0; //just for example
    $('#question').text(window[myStr + 'arrayquestions'][randomstart]);
    $('#q1').text(window[myStr + 'arrayquestions'][randomstart]);
    $('#q2').text(window[myStr + 'arrayquestions'][randomstart]);
}

handleQuestion('first');

but why not use an object

var questions = {
    first: {
         questions : ["", "", ""],
         answer1   : ["", "", ""],
         answer2   : ["", "", ""]
    },
    second: {
         ...etc
    }
}

that way you can access them like :

function handleQuestion(myStr) {
    var randomstart = 0; //just for example
    var obj = questions[myStr];

    $('#question').text(obj.questions[randomstart]);
    $('#q1').text(obj.answer1[randomstart]);
    $('#q2').text(obj.answer2[randomstart]);
}

handleQuestion('first');

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