How to find the parent JSON object vaue using the child object value dynamically in Javascript?

Question

var obj = [
{
    "name": "A1",
    "children": [
        {
            "name": "A1-level1-child1",
            "children": [
                {
                    "name": "A1-level2-child1",
                    "children": [
                        {
                            "name": "A1-level3-child1",
                            "children": []
                        },
                        {
                            "name": "A1-level3-child2",
                            "children": []
                        }
                    ]
                }
            ]
        },
        {
            "name": "A2-level1-child1",
            "children": []
        }
    ]   
},
{
    "name": "B1",
    "children": [
    ]   
}

];

From the above JSON object, if i check the value "A1-level3-child1", the function should give me its parent name as "A1-level2-child1". Same way, if i check for "A2-level1-child1",then it should be give me the parent value as "A1".

Does this answer your question? [access parent object in javascript](https://stackoverflow.com/questions/1789892/access-parent-object-in-javascript) — Jaydeep, Dec 30 '19 at 08:45

score 0 · Answer 1 · answered Dec 30 '19 at 09:05

GoGo this code.

var parentMap = {}
function getParentMap(arr, parent) {
    if (!(arr instanceof Array)) {
        return;
    }

    for (o of arr) {
        parentMap[o.name] = parent;
        if (o.children && o.children.length) {
            getParentMap(o.children, o);
            //getParentMap(o.children, o.name);
        }
    }
}

var arr = [{
    "name": "A1",
    "children": [{
            "name": "A1-level1-child1",
            "children": [{
                "name": "A1-level2-child1",
                "children": [{
                        "name": "A1-level3-child1",
                        "children": []
                    },
                    {
                        "name": "A1-level3-child2",
                        "children": []
                    }
                ]
            }]
        },
        {
            "name": "A2-level1-child1",
            "children": []
        }
    ]
},
{
    "name": "B1",
    "children": []
}];

getParentMap(obj, null);
parentMap["A1-level3-child1"].name

score 0 · Answer 2 · answered Dec 30 '19 at 09:25

0

If you can redefine this structure, you can add 'parent' on every node, so more easy to operate it.

answered Dec 30 '19 at 09:25

score 0 · Accepted Answer · answered Dec 30 '19 at 09:27

You could iterate the array or children and use a short circuit if the node is found.

function getParentName(array, name, parent = 'root') {
    var result;
    array.some(o => result = o.name === name && parent
                          || o.children && getParentName(o.children, name, o.name));
    return result;
}

var array = [{ name: "A1", children: [{ name: "A1-level1-child1", children: [{ name: "A1-level2-child1", children: [{ name: "A1-level3-child1", children: [] }, { name: "A1-level3-child2", children: [] }] }] }, { name: "A2-level1-child1", children: [] }] }, { name: "B1", children: [] }];

console.log(getParentName(array, "A1-level3-child1")); // A1-level2-child1
console.log(getParentName(array, "A2-level1-child1")); // A1

Thanks, it worked fine. I have tried with .filter() but this solution works well. Thanks a lot! — suresh mg, Dec 30 '19 at 11:22

How to find the parent JSON object vaue using the child object value dynamically in Javascript?

3 Answers3