Flatten is a function that turns a nested array 'glob' and transform it into a linear array

flatten.js

/**************************************************
Author: Maverick Peppers
Date: 8/29/2016

Transform a nested array glob into one linear array
 Input: 
 - Glob. A nested array.
 Returns:
 - Queue. A linear array.
 ***************************************************/
function flatten(glob) {
	var queue = []; // create a new empty array

  // Step through the contents
	for(var i = 0; i < glob.length; i++) {
	      // If the content at i is an array, recusively call this function on the contents
        if(Array.isArray(glob[i])) {
            // Append the returned array on at the end of the queue
            queue = queue.concat(flatten(glob[i]));
        } else { // Else, we have an isolated item
            queue.push(glob[i]); // simply push it at the end of the array
        }
    }
    
    // Returns the flattened array contents
    return queue;
}

/************************
TESTS
*************************/
function runFlattenTest() {
  var test1 = [[1,2,[3]],4];
  var out1  = flatten(test1);
  // output is [1,2,3,4]
  console.log(JSON.stringify(out1));

  var test2 = [[[1],2,[3]],4,[6,7,[8],9],5];
  var out2  = flatten(test2);
  // output is [1,2,3,4,6,7,8,9,5]
  console.log(JSON.stringify(out2));

  var test3 = [1, 2, 3, 4, 5, []];
  var out3  = flatten(test3);
  // output is [1,2,3,4,5]
  console.log(JSON.stringify(out3));
}