Build tree array from json in javascript

Question

I need to build this tree array from this json below, I still try using filter, map and reduce, but I can't achieve the result.

[{
 "code": "2",
 "name": "PENDING"
},{
 "code": "2.2",
 "name": "PENDING CHILDREN"
}, {
 "code": "2.2.01.01",
 "name": "PENDING CHILDREN CHILDREN"
}, {
 "code": "2.2.01.02",
 "name": "PENDING CHILDREN CHILDREN02"
}, {
 "code": "1",
 "name": "ACTIVE"
}, {
 "code": "1.1",
 "name": "ACTIVE CHILDREN"
}, {
 "code": "1.1.01",
 "name": "ACTIVE CHILDREN CHILDREN"
}]

but if need build this tree structuring by your code name

[{
 "code": "2",
 "name": "PENDING",
 "children": [{
 "code": "2.2",
 "name": "PENDING CHILDREN",
 "children": [{
 "code": "2.2.01.01",
 "name": "PENDING CHILDREN CHILDREN"
 }, {
 "code": "2.2.01.02",
 "name": "PENDING CHILDREN CHILDREN02"
 }]
 }]
},{
 "code": "1",
 "name": "ACTIVE",
 "children": [{
 "code": "1.1",
 "name": "ACTIVE CHILDREN",
 "children": [{
 "code": "1.1.01",
 "name": "ACTIVE CHILDREN CHILDREN"
 }]
 }]
}]

I try using reduce, but i dont understand build this logic with javascrtip. Follow my code below

var idToNodeMap = contas.reduce(function(map, node, i) {
 map[node.code] = node;
 node.children = [];
 return map;
});

• Nina Scholz: you have some kind of hole in your data, from 2.2 to 2.2.01.01.
• Evan Trimboli: What are the rules for the code?
• user663031: What does this have to do with JSON?

Answer 1

This may solve your issue

function ensureNode(code, name, root) {
 var last;
 var node = code.split(/\./g).reduce((prev, cur) => {
 last = (last && (last + '.' + cur)) || cur;
 if(!prev.children){
 prev.children = [];
 }
 var result = prev.children.find(item => item.code === last);
 if(!result) {
 prev.children.push(result = {code: last});
 }
 return result;
 }, root);
 node.name = name;
}
var data = [{
 "code": "2",
 "name": "PENDING"
},{
 "code": "2.2",
 "name": "PENDING CHILDREN"
}, {
 "code": "2.2.01.01",
 "name": "PENDING CHILDREN CHILDREN"
}, {
 "code": "2.2.01.02",
 "name": "PENDING CHILDREN CHILDREN02"
}, {
 "code": "1",
 "name": "ACTIVE"
}, {
 "code": "1.1",
 "name": "ACTIVE CHILDREN"
}, {
 "code": "1.1.01",
 "name": "ACTIVE CHILDREN CHILDREN"
}];
var result = {};
 
data.forEach(item => ensureNode(item.code, item.name, result));
 
console.log(result);

Answer 2

With sorted data, you could use an object for building the tree and an array for the reference of the parents.

var data = [{ "code": "2", "name": "PENDING" }, { "code": "2.2", "name": "PENDING CHILDREN" }, { "code": "2.2.01.01", "name": "PENDING CHILDREN CHILDREN" }, { "code": "2.2.01.02", "name": "PENDING CHILDREN CHILDREN02" }, { "code": "1", "name": "ACTIVE" }, { "code": "1.1", "name": "ACTIVE CHILDREN" }, { "code": "1.1.01", "name": "ACTIVE CHILDREN CHILDREN" }],
 tree = function (data, root) {
 var o = {}, last = [root], level = 0;
 o[root] = {};
 data.forEach(function (a) {
 var parent = root;
 while (level && last[level].length >= a.code.length) {
 level--;
 }
 parent = last[level];
 level++;
 last.length = level;
 last.push(a.code);
 o[a.code] = a;
 o[parent].children = o[parent].children || [];
 o[parent].children.push(a);
 });
 return o[root].children;
 }(data, '');
console.log(tree);

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