Converting flat structure to hierarchical

Question

I need to create function which will be able to convert flat object to recursive object. Here is my example: I have flat array:

var flatArray = [
    {
              


        

Answer 1

var flatArray = [
    {
        Description: "G",
        guid: "c8e63b35",
        parent: null,
    },
    {
        Description: "Z",
        guid: "b1113b35",
        parent: "c8e63b35",
    },
    {
        Description: "F",
        guid: "d2cc2233",
        parent: "b1113b35",
    },
    {
        Description: "L",
        guid: "a24a3b1a",
        parent: null,
    },
    {
        Description: "K",
        guid: "cd3b11caa",
        parent: "a24a3b1a",
    },      
];

//for printing
function htmlPrint(obj) {
  document.write('
'+JSON.stringify(obj,null,2)+'
');
};

var guids = {};
var roots = [];

flatArray.forEach(function(node){ 
  guids[node.guid] = node;       //save into a hash
  node.Children = [];            //make sure it has a children array
  //save it as root if it is a root
  if(node.parent === null){ roots.push(node);}
});
flatArray.forEach(function(node){ 
  //if it has a parent, add self to parent's children
  var parent = guids[node.parent]; 
  if(parent)  parent.Children.push(node); 
});
htmlPrint(roots);