Dynamically build 2D array Javascript

Question

I want to build a 2 dimensional array dynamically, but I'm having trouble.

answers and votes (single string arrays) will always be the same length;

I need an array like this:

var data = 
 [['Answer', 'Votes'],
 [answers[0], parseInt(votes[0])],
 [answers[1], parseInt(votes[1])],
 [answers[2], parseInt(votes[2])],
 ....
 ];

This doesn't work;

var data[];
var arrayLength = answers.length;
for (var i = 0; i < arrayLength; i++) {
 data += [answers[i], votes[i]]; //**Maybe the only line that needs tweaking?
}

• Jesse: does answers array has the same length with the votes array?

Answer 1

Try this:

var data = [];
data[0] = ['answers','votes']
var arrayLength = answers.length;
for (var i = 0; i < arrayLength; i++) {
 data[i+1]= [answers[i], parseInt(votes[i])]; 
}
//check
console.table(data)

Answer 2

var data = [];
var arrayLength = answers.length;
data[0] = ['Answer', 'Votes'];
for (var i = 1; i < arrayLength; i++) {
 data.push([answers[i], votes[i]]); /*It's not += but .push()*/
}

• Xlander: Ah yeah. I've missed it. Thanks for the notice.
• Colbs: he copied off my bad declaration ;) .. Thanks @Xlander

Answer 3

Try this:

var data = [];
var arrayLength = answers.length;
for (var i = 0; i < arrayLength; i++) {
 data.push([answers[i], votes[i]]);
}

Answer 4

Since you wrote answers [i] and votes[i] so, it seems your answers and votes are in two different array. so why the loop is needed.

Suppose answers and votes are:

var answers = ["A", "B", "C", "D", "E", "F"];
var votes = ["1", "2", "3", "4", "5", "6"];

building new array

var data = ["Answers", "Votes"];
data.Answers=answers;
data.Votes=votes;
console.log(data);