Flatten a multidimensional array

array_flatten.js

/**
 * Flatten array
 * 
 * Iterate over array elements.
 * Recurse into sub arrays.
 */

function flatten(a, f) {
      
    var f = f || []; // init result array
    
    a.forEach(function(e) {
        (e.push && e.slice && e.join) ? flatten(e, f) : f.push(e);
    });
    
    return f; // done :)
}

// array of random values
var a = [{ one: 1 }, 2, 3, 4, ['five', 6, [7, 8, [9, 10, ['eleven']]]], 12, [], 'thirteen'];

console.log(flatten(a));