Develop Reference

Get values for a matching key recursively from object

I have this json object
{
"data": {
"user": {
"user_info": {
"id": "AoGC2HQ9vedHmzcMX"
},
"product": [
{
"node": {
"id": "NzcxNzU2ODU1ODM1",
"feedback": {
"raters": {
"nodes": [
{
"id": "1",
"name": "Dan"
},
{
"id": "2",
"name": "Allen"
},
{
"id": "3",
"name": "Williams"
}
]
},
"commentors": {
"nodes": [
{
"id": "001",
"name": "Kent"
},
{
"id": "002",
"name": "Jay"
}
]
}
}
}
}
]
}
}
}
So how do I make it to get values of id If the parent property matches the desired key name, In this example I want to get all id's from raters.nodes only.
so expected result is
[1,2,3]
I know can do obj.data.user.product[0].node.feedback.raters.nodes and loop through that, but that is not how I want and the object tree occasionally changes.
I have used this recursive function
const recursiveSearch = (obj, searchKey, results = []) => {
const r = results;
Object.keys(obj).forEach(key => {
const value = obj[key];
if(key === searchKey && typeof value !== 'object'){
r.push(value);
}else if(typeof value === 'object'){
recursiveSearch(value, searchKey, r);
}
});
return r;
};
//returns all id's
While it works, it returns all id values, so how do I improve it? If not, how do I make this possible?

I think you want to really do this in 2 steps,..
First make a function to get the root node your looking for, and then you can just use map like normal.
Below is an example.
var data = JSON.parse("{\"data\":{\"user\":{\"user_info\":{\"id\":\"AoGC2HQ9vedHmzcMX\"},\"product\":[{\"node\":{\"id\":\"NzcxNzU2ODU1ODM1\",\"feedback\":{\"raters\":{\"nodes\":[{\"id\":\"1\",\"name\":\"Dan\"},{\"id\":\"2\",\"name\":\"Allen\"},{\"id\":\"3\",\"name\":\"Williams\"}]},\"commentors\":{\"nodes\":[{\"id\":\"001\",\"name\":\"Kent\"},{\"id\":\"002\",\"name\":\"Jay\"}]}}}}]}}}");
function getRoot(data, search) {
function get(path, data) {
for (const [k, v] of Object.entries(data)) {
if (v instanceof Object) {
const pp = `${path}.${k}`;
if (pp.slice(-search.length) === search) {
return v;
}
const r = get(`${path}.${k}`, v);
if (r) return r;
}
}
}
return get('', data);
}
const r = getRoot(data, 'raters.nodes');
console.log(r && r.map(i => i.id));

How to get the key value from nested object

I am having below object where I am trying to get all the id values.
[{
"type": "test",
"id": "100",
"values": {
"name": "Alpha"
},
"validations": []
}, {
"type": "services",
"validations": [{
"id": "200",
"name": "John",
"selection": [{
"id": "300",
"values": {
"name": "Blob"
}
}]
}]
}]
Using the below code, I am getting only the first id value. Is there any way to get all the id values from the nested object without using any external module.
for (var prop in obj) {
console.log(prop)
if (prop === key) {
set.push(prop);
}
}
Expected Output
[100,200,300] //all id values

You can use a JavaScript function like below to get the nested properties:
function findProp(obj, key, out) {
var i,
proto = Object.prototype,
ts = proto.toString,
hasOwn = proto.hasOwnProperty.bind(obj);
if ('[object Array]' !== ts.call(out)) out = [];
for (i in obj) {
if (hasOwn(i)) {
if (i === key) {
out.push(obj[i]);
} else if ('[object Array]' === ts.call(obj[i]) || '[object Object]' === ts.call(obj[i])) {
findProp(obj[i], key, out);
}
}
}
return out;
}
Check this Fiddle for a working solution.

Using Object.keys
function findProp(obj, prop) {
var result = [];
function recursivelyFindProp(o, keyToBeFound) {
Object.keys(o).forEach(function (key) {
if (typeof o[key] === 'object') {
recursivelyFindProp(o[key], keyToBeFound);
} else {
if (key === keyToBeFound) result.push(o[key]);
}
});
}
recursivelyFindProp(obj, prop);
return result;
}
// Testing:
var arr = [{
"type": "test",
"id": "100",
"values": {
"name": "Alpha"
},
"validations": []
}, {
"type": "services",
"validations": [{
"id": "200",
"name": "John",
"selection": [{
"id": "300",
"values": {
"name": "Blob"
}
}]
}]
}];
console.log(findProp(arr, "id"));

To get the keys from nested objects, you first need to put your code in a function, then for each of the top-level keys, check if it's an array or object. If it is, just call your function again from within that function (weird, I know.) Just make sure you don't skip the check of whether it's an object. You'll get stuck in an infinite loop. Something like this:
function parseObjectKeys(obj) {
for (var prop in obj) {
console.log(prop)
var sub = obj[prop]
if (typeof(sub) == "object") {
parseObjectKeys(sub);
}
}
}
Here's a more complex example:
https://jsfiddle.net/tfqLnzLm/1/

You can use a XPath styled json parser like JSONPath. The version I'm presenting here is a extended version I did here:
function jsonPath(obj,expr,arg){var P={resultType:arg&&arg.resultType||"VALUE",result:[],normalize:function(e){var t=[];return e.replace(/[\['](\??\(.*?\))[\]']/g,function(e,r){return"[#"+(t.push(r)-1)+"]"}).replace(/'?\.'?|\['?/g,";").replace(/;;;|;;/g,";..;").replace(/;$|'?\]|'$/g,"").replace(/#([0-9]+)/g,function(e,r){return t[r]})},asPath:function(e){for(var t=e.split(";"),r="$",a=1,n=t.length;n>a;a++)r+=/^[0-9*]+$/.test(t[a])?"["+t[a]+"]":"['"+t[a]+"']";return r},store:function(e,t){return e&&(P.result[P.result.length]="PATH"==P.resultType?P.asPath(e):t),!!e},trace:function(e,t,r){if(e){var a=e.split(";"),n=a.shift();if(a=a.join(";"),t&&t.hasOwnProperty(n))P.trace(a,t[n],r+";"+n);else if("*"===n)P.walk(n,a,t,r,function(e,t,r,a,n){P.trace(e+";"+r,a,n)});else if(".."===n)P.trace(a,t,r),P.walk(n,a,t,r,function(e,t,r,a,n){"object"==typeof a[e]&&P.trace("..;"+r,a[e],n+";"+e)});else if(/,/.test(n))for(var l=n.split(/'?,'?/),s=0,c=l.length;c>s;s++)P.trace(l[s]+";"+a,t,r);else/^\(.*?\)$/.test(n)?P.trace(P.eval(n,t,r.substr(r.lastIndexOf(";")+1))+";"+a,t,r):/^\?\(.*?\)$/.test(n)?P.walk(n,a,t,r,function(e,t,r,a,n){P.eval(t.replace(/^\?\((.*?)\)$/,"$1"),a[e],e)&&P.trace(e+";"+r,a,n)}):/^(-?[0-9]*):(-?[0-9]*):?([0-9]*)$/.test(n)&&P.slice(n,a,t,r)}else P.store(r,t)},walk:function(e,t,r,a,n){if(r instanceof Array)for(var l=0,s=r.length;s>l;l++)l in r&&n(l,e,t,r,a);else if("object"==typeof r)for(var c in r)r.hasOwnProperty(c)&&n(c,e,t,r,a)},slice:function(e,t,r,a){if(r instanceof Array){var n=r.length,l=0,s=n,c=1;e.replace(/^(-?[0-9]*):(-?[0-9]*):?(-?[0-9]*)$/g,function(e,t,r,a){l=parseInt(t||l),s=parseInt(r||s),c=parseInt(a||c)}),l=0>l?Math.max(0,l+n):Math.min(n,l),s=0>s?Math.max(0,s+n):Math.min(n,s);for(var o=l;s>o;o+=c)P.trace(o+";"+t,r,a)}},eval:function(x,_v,_vname){try{return $&&_v&&eval(x.replace(/#/g,"_v"))}catch(e){throw new SyntaxError("jsonPath: "+e.message+": "+x.replace(/#/g,"_v").replace(/\^/g,"_a"))}}},$=obj;return expr&&obj&&("VALUE"==P.resultType||"PATH"==P.resultType)?(P.trace(P.normalize(expr).replace(/^\$;/,""),obj,"$"),P.result.length?P.result:!1):void 0}
// some extensions I have added to JSONPath
var jsonPathStore = function(obj,path,values) {
var maps=jsonPath(obj, path,{resultType:"PATH"})
maps.map(function(item,index) {
return eval( '(' + item.replace(/\$/,"obj") + '="' + values[index] +'"' + ')' );
})
}
var jsonPathDelete = function(obj,path) {
var maps=jsonPath(obj, path,{resultType:"PATH"})
maps.map(function(item,index) {
return eval( '(' + 'delete ' + item.replace(/\$/,"obj") + ')' );
})
}
var jsonPathRead = function(obj,path) {
var maps=jsonPath(obj, path,{resultType:"PATH"})
return maps.map(function(item,index) {
return eval( '(' + item.replace(/\$/,"obj") + ')' );
})
}
var jsonObject = [{
"type": "test",
"id": "100",
"values": {
"name": "Alpha"
},
"validations": []
}, {
"type": "services",
"validations": [{
"id": "200",
"name": "John",
"selection": [{
"id": "300",
"values": {
"name": "Blob"
}
}]
}]
}]
// this XPath will read all the id properties starting from the root element
console.log( "jsonPathRead All Ids" + JSON.stringify(jsonPathRead(jsonObject,"$..id"), null, 2) )

function getIds(obj) {
for (var x in obj) {
if (typeof obj[x] === 'object') {
getIds(obj[x]);
} else if (x === 'id') {
console.log(obj.id);
}
}
}

Compare two arrays and update with the new values by keeping the existing objects using javascript

Below are my two arrays .I want to compare them and the resultant array should contain the updated values.Id's are common..
The arrays spans to n levels ie., there is no fixed levels..
The first array ie., the array before updation..
var parentArray1=[
{
"id": 1,
"name": "test",
"context": [
{
"id": 1.1,
"name": "test 1.1"
}
]
},
{
"id": 2,
"name": "test"
},
{
"id": 3,
"name": "test",
"context": [
{
"id": 3.1,
"name": "test 3.1"
}
]
},
{
"id": 4,
"name": "test"
}
]
The operations that i performed are
1.Adding a new Item
2.Updating an existing item
As a result of these two operations the changed values I will be getting in a different array..
ie.,
var changedArray=
[
{
"id": 1,
"name": "test1",
"context": [
{
"id": 1.1,
"name": "Changed test 1.1"
}
]
},
{
"id": 5,
"name": "test5"
}
]
Now I have written a generic function that loops through the parentArray1 and using the unique propertiesI need to either add a new item,if the item is there in the changedArray or update an existing item at any level
The resultant array should be ..
[
{
"id": 1,
"name": "test",
"context": [
{
"id": 1.1,
"name": "Changed test 1.1"
}
]
},
{
"id": 2,
"name": "test"
},
{
"id": 3,
"name": "test",
"context": [
{
"id": 3.1,
"name": "test 3.1"
}
]
},
{
"id": 4,
"name": "test"
},
{
"id": 5,
"name": "test5"
}
]
Generic function:
compareArray(parentArray1, changedArray, ["id"]);
function compareArray(array1, array2, propertyArray) {
var newItem = new Array();
array2.map(function(a1Item) {
array1.map(function(a2Item) {
/ If array loop again /
if (a2Item.constructor === Array) {
compareArray(a2Item, a1Item)
} else {
/ loop the property name to validate /
propertyArray.map(function(property) {
if (a2Item[property]) {
if (a2Item[property] === a1Item[property]) {
a2Item = a1Item
} else {
var isAvailable = _.find(newItem, function(item) {
return item[property] === a1Item[property]
})
if (!isAvailable) {
newItem.push(a1Item);
}
}
}
})
}
});
});
/ Insert the new item into the source array /
newItem.map(function(item) {
array1.push(item);
});
console.log("After Compare : " + array1);
}

I suggest to use a temporary object for the reference to the id and update if exist or push if not exist.
var parentArray1 = [{ "id": 1, "name": "test", "context": [{ "id": 1.1, "name": "test 1.1" }] }, { "id": 2, "name": "test" }, { "id": 3, "name": "test", "context": [{ "id": 3.1, "name": "test 3.1" }] }, { "id": 4, "name": "test" }],
changedArray = [{ "id": 1, "name": "test1", "context": [{ "id": 1.1, "name": "Changed test 1.1" }] }, { "id": 5, "name": "test5" }];
function insert(array, data) {
function iter(array) {
array.forEach(function (a) {
if (!('id' in a)) {
return;
}
if (o[a.id] !== a) {
o[a.id] = a;
}
Object.keys(a).forEach(function (k) {
Array.isArray(a[k]) && iter(a[k]);
});
});
}
var o = {};
iter(array);
data.forEach(function (a) {
if (o[a.id]) {
Object.keys(a).forEach(function (k) {
o[a.id][k] = a[k];
});
return;
}
array.push(a);
});
}
insert(parentArray1, changedArray);
document.write('<pre>' + JSON.stringify(parentArray1, 0, 4) + '</pre>');

This is what I came up with:
function sameKeys(o1, o2, keys) {
for (var i = 0; i < keys.length; i++) {
var key = keys[i];
if (!o1.hasOwnProperty(key) || !o2.hasOwnProperty(key))
throw 'compared objects do not have the key ' + key;
if (o1[key] !== o2[key])
return false;
}
return true;
}
function isNothing(o) {
return typeof(o) === 'undefined' || o === null;
}
// this does not work if objects have functions as properties
function clone(o) {
if (isNothing(o))
return o;
return JSON.parse(JSON.stringify(o));
}
function extend(o1, o2, keys) {
if (isNothing(o2))
return;
if (isNothing(o1))
throw ('first parameter cannot be empty');
if (typeof(o1) != 'object' || typeof(o2) != 'object')
throw ('extend only works on objects');
Object.keys(o2).forEach(function (key) {
var newVal = o2[key];
if (o1.hasOwnProperty(key)) {
if (isNothing(newVal)) {
delete o1[key];
} else
if (Array.isArray(newVal)) {
compareArray(o1[key], newVal, keys);
} else {
switch (typeof(newVal)) {
case 'object':
extend(o1[key], newVal, keys);
break;
case 'boolean':
case 'number':
case 'string':
o1[key] = newVal;
break;
default:
throw 'not supported property type: ' + typeof(newVal);
}
}
} else {
o1[key] = clone(newVal);
}
});
}
function removeFromArray(arr, ids, keyArray) {
var indexes = [];
var it1s = arr.forEach(function (it, idx) {
if (sameKeys(ids, it, keyArray)) {
indexes.push(idx);
} else {
Object.keys(it).forEach(function (key) {
var newVal = it[key];
if (Array.isArray(newVal)) {
removeFromArray(it[key], ids, keyArray);
}
});
}
});
if (indexes.length) {
if (indexes.length > 1)
throw 'found multiple possible objects for the same key combination'
arr.splice(indexes[0], 1);
}
}
function compareArray(a1, a2, keyArray) {
a2.forEach(function (it2) {
var it1s = a1.filter(function (it) {
return sameKeys(it2, it, keyArray);
});
var it1;
if (!it1s.length) {
it1 = clone(it2);
a1.push(it1);
} else {
if (it1s.length > 1)
throw 'found multiple possible objects for the same key combination'
it1 = it1s[0];
extend(it1, it2, keyArray);
}
if (it2.removedIds) {
it2.removedIds.forEach(function (ids) {
removeFromArray(a1, ids, keyArray);
});
}
});
}
Use it with compareArray(parentArray1,changedArray,['id']);
Note that it would not work with objects that contain functions. Also, if the arrays would be large, perhaps a better solution is to sort both arrays by key, then always look from the last found object up. That's all I got for now.
Updated it with some concepts from Nina and some clearing of the code.
As I understood it, you only want to add properties. So extend({a: {b: 2}},{a:{c:3}}) will result in {a: {b:2,c:3}}. If this is not what you wanted, let me know.
I also added functionality for removing ids. If any of the objects in the array contains a removedIds array of the form [{id: 4},{id: 5}] then the items with those ids will be removed from the original array.

Slight modification on code, to satisfy your conditions. Try it!
function compareArray(originalArray, destinationArray, propertyArray) {
var newItem = new Array(), processedItem = new Array();
for (var i = 0; i < originalArray.length; i++) {
var sourceElement = originalArray[i];
for (var j = 0; j < destinationArray.length; j++) {
var destinationElement = destinationArray[j];
var isUpdated = false;
if (sourceElement.constructor === Array) {
compareArray(sourceElement, destinationElement, propertyArray);
} else {
/* loop the property name to validate */
propertyArray.map(function(property) {
if (sourceElement[property]) {
if (sourceElement[property] === destinationElement[property]) {
originalArray[i] = _.clone(destinationElement);
isUpdated = true;
return;
} else {
var isAvailable = _.find(newItem, function(item) {
return item[property] === destinationElement[property];
});
if (!isAvailable) {
var isAlreadyProcessed = _.find(processedItem, function(item) {
return item[property] === destinationElement[property];
});
if(!isAlreadyProcessed){
newItem.push(destinationElement);
}
}
}
}
});
}
if (isUpdated === true) {
break;
}
}
processedItem.push(sourceElement);
}
newItem.map(function(item) {
originalArray.push(item);
});
return originalArray;
}

How do I loop through deeply nested json object

var City ={
"City1": [{"name": "Place 1"},{"name": "Place 2"},{"name": "Place 3"}],
"City2":[{"name":"My Place 1"},{"name":"My Place 2"},{"name":"My Place 3"}],
"City3":[{"name":"My Place 1"},{"name":"My Place 2"},{"name":"My Place 3"}]
};
I want to use JavaScript to loop to get the first city name, and then loop to get its places, then get the second city and its places and so on.

You could use a for loop to go through all properties of the City object:
for (var key in City) {
if (City.hasOwnProperty(key)) {
var values = City[key];
// "key" will be City1, City2, ...
// "values" will be the corresponding array through which
// you can loop
}
}

function nestedLoop(obj) {
const res = {};
function recurse(obj, current) {
for (const key in obj) {
let value = obj[key];
if(value != undefined) {
if (value && typeof value === 'object') {
recurse(value, key);
} else {
// Do your stuff here to var value
res[key] = value;
}
}
}
}
recurse(obj);
return res;
}

Try utilizing Object.keys() , Array.prototype.forEach()
var City = {
"City1": [{
"name": "Place 1"
}, {
"name": "Place 2"
}, {
"name": "Place 3"
}],
"City2": [{
"name": "My Place 1"
}, {
"name": "My Place 2"
}, {
"name": "My Place 3"
}],
"City3": [{
"name": "My Place 1"
}, {
"name": "My Place 2"
}, {
"name": "My Place 3"
}]
};
Object.keys(City).forEach(function(value, key) {
console.log(value);
City[value].forEach(function(v, k) {
console.log(v.name)
})
});

for (let key in City) {
let value = City[key];
console.log(key);
for (i = 0; i <= value.length; i++) {
console.log(value[i]);
}
}

finding all occurance of a particular field value inside object tree

I am trying to print the values of all the occurence of a field "term".. with the program Ive written it only returns the first occurence.. Is it possible to get whole occurence?
http://jsfiddle.net/AQ5WK/
var data = {
"_index": "test",
"_type": "news",
"_source": {
"partnerName": "propertyFile 9",
"relatedSources": "null",
"entityCount": "50",
"Categories": {
"Types": {
"Events": [{
"count": 1,
"term": "Time",
"Time": [{
"term": "Dec 9",
"Dec_9": [{
"count": 1,
"term": "2012"
}]
}]
}, {
"count": 4,
"term": "News",
"News": [{
"term": "Germany",
"Germany": [{
"count": 1,
"term": "Election"
}],
"currency": "Euro (EUR)"
}, {
"term": "Egypt",
"Egypt": [{
"count": 1,
"term": "Revolution"
}]
}]
}]
}
}
}};
var findDeepKey = function(obj, key){
var results = [];
if (typeof obj !== 'object') return null;
for (var k in obj) {
if (k === key) return obj[k];
}
for (var k in obj) {
if (typeof obj[k] === 'object') {
if (obj[k].length) {
for (var i = 0, il = obj[k].length; i < il; i++) {
results.push(findDeepKey(obj[k][i], key));
}
} else {
for (var kk in obj[k]) {
if (kk === key) return obj[k][kk];
results.push(findDeepKey(obj[k][kk], key));
}
}
}
}
for (var i = 0, il = results.length; i < il; i++) {
if (results[i] !== null)
return results[i];
}};
alert(findDeepKey(data, 'term'));
​

I am trying to print the values of all the occurence of a field "term"
Anywhere it exists at any level of the object tree? That's a recursive-descent search: Live example | source
function findProps(name, data, results) {
var key, value;
// If we weren't given a results array, create one
if (Object.prototype.toString.call(results) !== "[object Array]") {
results = [];
}
// Is it an object (including an array)?
if (typeof data === "object") {
// Yes, loop through its properties
for (key in data) {
// Does it have an "own" property with this name?
// (I assume you only want "own" properties, not
// properties inherited from the prototype chain).
if (data.hasOwnProperty(key)) {
// Yes, get the value
value = data[key];
// Is this our property?
if (key === name) {
// Remember it
results.push(value);
}
// Recurse into the value?
if (typeof value === "object") {
// Yes
findProps(name, value, results);
}
}
}
}
// All done
return results;
}
var terms = findProps("term", data);
display("Found 'term' " + terms.length +
" time(s): " + terms.join(", "));