Convert JavaScript array of 2 element arrays into object key value pairs

Question

What is the fastest algorithm for getting from something like this:

var array = [ [1,\'a\'], [2,\'b\'], [3,\'c\'] ];

to something like this

Answer 1

You could indeed use Array.prototype.reduce:

function objectify(array) {
    return array.reduce(function(p, c) {
         p[c[0]] = c[1];
         return p;
    }, {});
}

where p is the result of the previous iteration, initially {}, and c is the current element of the array.

It's unlikely to be any faster than array.forEach, but it is IMHO cleaner. I don't believe there's any simpler implementation than this.

NB: a function to do exactly this already exists in the Underscore library: _.object(array)