I have an array of numbers, like so:
[5, 29, 1, 5, 4919, 109, 17]
I'd like to turn that into pairs of number based on the index in the array, like this:
[[0, 5], [1, 29], [2, 5], [3, 4919], [4, 109], [5, 17]]
How can I do that with javascript?
[5, 29, 1, 5, 4919, 109, 17].map(function(x,i){return [i,x];})
The other answer suggests using map which is a fine solution and probably what I would use in my own code, but map was introduced in ECMAScript 5, so it might not work in older browsers (without polyfill).
If you need something more universal, a very simple method would be something like this:
var input = [5, 29, 1, 5, 4919, 109, 17];
var output = [];
for (var i = 0; i < input.length; i++)
output.push([i, input[i]]);
Or this:
var input = [5, 29, 1, 5, 4919, 109, 17];
var output = Array(input.length);
for (var i in input)
output[i] = [i, input[i]];
Here's a library that adds those missing methods for older browsers: http://augmentjs.com/ ~ 5.501 kb
