I have following flat array of data, primarily with levels, and which is ordered. Based on the levels, I need to create a tree hierarchical array.
Following is the input:
[
{
"position": "CEO",
"level": 1,
"name": "Adam"
},
{
"position": "President",
"level": 2,
"name": "Eva"
},
{
"position": "Senior Vice President",
"level": 3,
"name": "Thein"
},
{
"position": "Vice President",
"level": 4,
"name": "Rick"
},
{
"position": "Vice President",
"level": 4,
"name": "Rosh"
},
{
"position": "Vice President",
"level": 4,
"name": "Jenny"
},
{
"position": "Vice President",
"level": 4,
"name": "Tim"
},
{
"position": "Vice President",
"level": 4,
"name": "Gin"
},
{
"position": "President",
"level": 2,
"name": "Nisham"
},
{
"position": "Senior Vice President",
"level": 3,
"name": "Gil"
},
{
"position": "Vice President",
"level": 4,
"name": "Lew"
},
{
"position": "Vice President",
"level": 4,
"name": "Dan"
},
{
"position": "Vice President",
"level": 4,
"name": "Henry"
}
]
And the expected output is:
[
{
"position": "CEO",
"level": 1,
"name": "Adam",
"children": [
{
"position": "President",
"level": 2,
"name": "Eva",
"children": [
{
"position": "Senior Vice President",
"level": 3,
"name": "Thein",
"children":[
{
"position": "Vice President",
"level": 4,
"name": "Rick"
},
{
"position": "Vice President",
"level": 4,
"name": "Rosh"
},
{
"position": "Vice President",
"level": 4,
"name": "Jenny"
},
{
"position": "Vice President",
"level": 4,
"name": "Tim"
},
{
"position": "Vice President",
"level": 4,
"name": "Gin"
}
]
}
]
},
{
"position": "President",
"level": 2,
"name": "Nisham",
"children":[
{
"position": "Senior Vice President",
"level": 3,
"name": "Gil",
"children":[
{
"position": "Vice President",
"level": 4,
"name": "Lew"
},
{
"position": "Vice President",
"level": 4,
"name": "Dan"
},
{
"position": "Vice President",
"level": 4,
"name": "Henry"
}
]
}
]
}
]
}
]
I came across many stacks but all of them have a id and parent_id as a link. However, in this data, there is no id link between the array items.
I tried following code so far:
let root = {};
let i = 0;
data.forEach(el => {
if (el["level"] == 1) {
root = el;
root.children = [];
}
if (el["level"] == 2) {
root.children.push(el);
root.children[i].children = [];
}
if (el["level"] == 3) {
root.children[i].children.push(el);
root.children[i].children[i].children = [];
}
if (el["level"] == 4) {
root.children[i].children[i].children.push(el);
root.children[i].children[i].children[i].children = [];
}
i++;
});
It gives output for the first pass, but throws error later. I know it's not right and levels are hard coded, but that's the try so far.
You could use nearly an one-liner by using an levels array which keeps all levels of the last inserted objects.
const
data = [{ position: "CEO", level: 1, name: "Adam" }, { position: "President", level: 2, name: "Eva" }, { position: "Senior Vice President", level: 3, name: "Thein" }, { position: "Vice President", level: 4, name: "Rick" }, { position: "Vice President", level: 4, name: "Rosh" }, { position: "Vice President", level: 4, name: "Jenny" }, { position: "Vice President", level: 4, name: "Tim" }, { position: "Vice President", level: 4, name: "Gin" }, { position: "President", level: 2, name: "Nisham" }, { position: "Senior Vice President", level: 3, name: "Gil" }, { position: "Vice President", level: 4, name: "Lew" }, { position: "Vice President", level: 4, name: "Dan" }, { position: "Vice President", level: 4, name: "Henry" }],
result = [],
levels = [result];
data.forEach(o => levels[o.level - 1].push({ ...o, children: levels[o.level] = []}));
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }An approach without unused children arrays.
const
data = [{ position: "CEO", level: 1, name: "Adam" }, { position: "President", level: 2, name: "Eva" }, { position: "Senior Vice President", level: 3, name: "Thein" }, { position: "Vice President", level: 4, name: "Rick" }, { position: "Vice President", level: 4, name: "Rosh" }, { position: "Vice President", level: 4, name: "Jenny" }, { position: "Vice President", level: 4, name: "Tim" }, { position: "Vice President", level: 4, name: "Gin" }, { position: "President", level: 2, name: "Nisham" }, { position: "Senior Vice President", level: 3, name: "Gil" }, { position: "Vice President", level: 4, name: "Lew" }, { position: "Vice President", level: 4, name: "Dan" }, { position: "Vice President", level: 4, name: "Henry" }],
result = [],
levels = [{ children: result }];
data.forEach(function (o) {
levels[o.level - 1].children = levels[o.level - 1].children || [];
levels[o.level - 1].children.push(levels[o.level] = o);
});
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }