I need to create the object property from array values and assign some values to that for example
var main_obj = {};
var dynamic_array = ["value1", "value2", "value3", "value4"];
From dynamic_array I need to create main_obj like:
main_obj[value1][value2][value3] = some_value;
Please give me some suggestions.
dynamic_array.forEach(function(prop){
main_obj[prop] = some_value;
});
this is another way
var dynamic_array = ["value1","value2","value3"];
var value = 'your value';
function createobj(dynamic_array,value){
var count = dynamic_array.length;
var text= '';
var ended = '';
for(var i = 0; i < count; i++){
text += '{"'+dynamic_array[i]+'":';
ended +='}';
}
text += '"'+value+'"'+ended;
return JSON.parse(text);
}
console.log(createobj(dynamic_array,value));
Trying to interpretate your question, this may be a solution to what you are looking for:
function createNestedProperties(obj, array, value) {
var result = {};
var result_tmp = obj;
var i = 0;
while (i < array.length) {
if (i < (array.length - 1))
result_tmp[array[i]] = {};
else
result_tmp[array[i]] = value;
result_tmp = result_tmp[array[i]];
i++;
}
return obj;
}
used this way:
var main_obj = {"value1":{"value2":{"value3":{}}}};
var dynamic_array = ["value1", "value2", "value3"];
main_obj = createNestedProperties(main_obj, dynamic_array, {"value_Z":"new value"});
Resulting object:
{"value1":{"value2":{"value3":{"value_Z":"new value"}}}}
This function would override existing properties in main_obj if already there.
i parse through the object recursively rather than building that jQuery - How to recursively loop over an object's nested properties?
function recursiveIteration(main_obj) {
for (var property in main_obj) {
if (property == value3)
{
main_obj[property] = {"value4":test};
}
else
{
recursiveIteration(main_obj[property]);
}
}
}
recursiveIteration(main_obj);
Related
I'm trying to create a JS object dynamically providing a key and a value. The key is in dot notation, so if a string like car.model.color is provided the generated object would be:
{
car: {
model: {
color: value;
}
}
}
The problem has a trivial solution if the key provided is a simple property, but i'm struggling to make it work for composed keys.
My code:
function (key, value) {
var object = {};
var arr = key.split('.');
for(var i = 0; i < arr.length; i++) {
object = object[arr[i]] = {};
}
object[arr[arr.length-1]] = value;
return object;
}
your slightly modified code
function f(key, value) {
var result = object = {};
var arr = key.split('.');
for(var i = 0; i < arr.length-1; i++) {
object = object[arr[i]] = {};
}
object[arr[arr.length-1]] = value;
return result;
}
In the loop you should set all of the props but the last one.
Next set the final property and all set.
If you're using lodash you could use _.set(object, path, value)
const obj = {}
_.set(obj, "car.model.color", "my value")
console.log(obj)
<script src="https://cdn.jsdelivr.net/npm/lodash#4.17.15/lodash.min.js"></script>
Use namespace pattern, like the one Addy Osmani shows: http://addyosmani.com/blog/essential-js-namespacing/
Here's the code, pasted for convenience, all credit goes to Addy:
// top-level namespace being assigned an object literal
var myApp = myApp || {};
// a convenience function for parsing string namespaces and
// automatically generating nested namespaces
function extend( ns, ns_string ) {
var parts = ns_string.split('.'),
parent = ns,
pl, i;
if (parts[0] == "myApp") {
parts = parts.slice(1);
}
pl = parts.length;
for (i = 0; i < pl; i++) {
//create a property if it doesnt exist
if (typeof parent[parts[i]] == 'undefined') {
parent[parts[i]] = {};
}
parent = parent[parts[i]];
}
return parent;
}
// sample usage:
// extend myApp with a deeply nested namespace
var mod = extend(myApp, 'myApp.modules.module2');
function strToObj(str, val) {
var i, obj = {}, strarr = str.split(".");
var x = obj;
for(i=0;i<strarr.length-1;i++) {
x = x[strarr[i]] = {};
}
x[strarr[i]] = val;
return obj;
}
usage: console.log(strToObj("car.model.color","value"));
I would use a recursive method.
var createObject = function(key, value) {
var obj = {};
var parts = key.split('.');
if(parts.length == 1) {
obj[parts[0]] = value;
} else if(parts.length > 1) {
// concat all but the first part of the key
var remainingParts = parts.slice(1,parts.length).join('.');
obj[parts[0]] = createObject(remainingParts, value);
}
return obj;
};
var simple = createObject('simple', 'value1');
var complex = createObject('more.complex.test', 'value2');
console.log(simple);
console.log(complex);
(check the console for the output)
Here's a recursive approach to the problem:
const strToObj = (parts, val) => {
if (!Array.isArray(parts)) {
parts = parts.split(".");
}
if (!parts.length) {
return val;
}
return {
[parts.shift()]: strToObj(parts, val)
};
}
How to count the JSON object and on the basis of count take the same output
var obj =
[
{"id":"0","name":"Mike Johnson","group":1},
{"id":"1","name":"Bob Smith","group":2},
{"id":"2","name":"Richard Thomas","group":3},
{"id":"3","name":"Betty White","group":16},
{"id":"4","name":"Tim Thompson","group":3},
{"id":"5","name":"Carl Lewis","group":16},
{"id":"6","name":"Kathy Towers","group":3},
{"id":"7","name":"Billy Bob","group":1},
{"id":"8","name":"Sally Bailey","group":1}
];
First I would like the count after it on the basis of count. I want same output like input.
for Count:-
var count = 0;
function getCount() {
for (var i = 0; i < obj.length; i++) {
count++;
}
return count;
}
for output :-
function showDetails() this is not giving the proper output
{
for(var j=0; j< count; j++){
obj.push([{j}]);
}
alert(obj.name);
}
alert(showDetails());
And I want an output like:-
var obj =
[
{"id":"0","name":"Mike Johnson","group":1},
{"id":"1","name":"Bob Smith","group":2},
{"id":"2","name":"Richard Thomas","group":3},
{"id":"3","name":"Betty White","group":16},
{"id":"4","name":"Tim Thompson","group":3},
{"id":"5","name":"Carl Lewis","group":16},
{"id":"6","name":"Kathy Towers","group":3},
{"id":"7","name":"Billy Bob","group":1},
{"id":"8","name":"Sally Bailey","group":1}
];
Can anybody help me please?
var data ="January,February,March,April,May,June,July,August,September,October";
var obj = data.split(',').map((item)=>{
return {
name:item
}
});
obj will be the desired output
var str = "January,February,March,April,May,June,July,August,September,October";
var arr = str.split(',').map(function(v) {
return {name: v};
});
console.log(arr);
var str = "January,February,March,April,May,June,July,August,September,October";
var months = str.split(",");
var result = [];
for (i in months)
{
var month = {};
month.name = months[i];
//you can do more things else here, for example:
//month.monthOfYear = (i+1);
//month.numberOfDay = 123123123;
result.push(month);
}
You can do something like this:
var array = string.split(",");
var finalArray = [];
array.forEach(function(item){
var obj = {
name: item
}
finalArray.push(obj);
});
console.log(finalArray);
MDN reference
use var array = string.split(',');
For a more ES2015 heavy version. Constants, arrow function and implicit return statement.
const str = 'January,February,March,April,May,June,July,August,September,October'
const result = str.split(',').map(name => ({name}))
console.log(result)
I am trying to set one of the nested subobject properties, but the nested level is dynamic.
how can I dynamically set the nested properties?
It's working only one level properties,i can't set next inner level....
my code:
function deSerialize(qualifiedNameArray, currentIndex, resultJSON, valueToBeInitializedForFinalNode)
{
if (currentIndex == (qualifiedNameArray.length - 1)){
resultJSON [qualifiedNameArray[currentIndex++]] = valueToBeInitializedForFinalNode;
}
else
{
resultJSON [qualifiedNameArray[currentIndex++]] = {};
}
if (currentIndex < qualifiedNameArray.length)
deSerialize( qualifiedNameArray, currentIndex, resultJSON, valueToBeInitializedForFinalNode);
return resultJSON;
}
var results = {"columnname":"person.name.first", "varcharvalue":"david", "objecttype" : "user"};
var valueToBeInitializedForFinalNode = results["varcharvalue"];
var qualifiedNameArray = results["columnname"].split('.');
var resultJSON = {};
deSerialize(qualifiedNameArray, 0, resultJSON, valueToBeInitializedForFinalNode);
A simple solution might be, not sure if this is what you are looking for:
function makeObj(arry, initValue){
var obj = {}, objRef = obj, idx = 0;
while(idx < arry.length -1){
obj[arry[idx]] = {};
obj = obj[arry[idx]];
idx++;
}
obj[arry[idx]] = initValue;
return objRef;
}
usage:
resultJSON = makeObj( qualifiedNameArray, valueToBeInitializedForFinalNode);
another way is:
function makeObj(objRef, arry, initValue){
var obj = objRef, idx = 0;
while(idx < arry.length -1){
if(!obj[arry[idx]]) obj[arry[idx]] = {};
obj = obj[arry[idx]];
idx++;
}
if(!obj[arry[idx]]) obj[arry[idx]] = initValue;
}
this way, you do not change any values that might have been already present, usage:
makeObj( resultJSON, qualifiedNameArray, valueToBeInitializedForFinalNode);
My function is
var MyArray= [];
$('input:checked').each(function(index) {
MyArray= ($(this).attr('id') + ":" + $(this).val()).length;
});
My array is
Array [ "1:R1", "2:R2", "3:R3", "4:R1" ]
I would like to count the differents values and to get this object
Object {R1:2, R2:1, R3:1}
Instead of putting the values in an array and then get the values out of the array to process them and create an object, put them in the object to start with:
var map = {};
$('input:checked').each(function() {
var key = $(this).val();
if (key in map) {
map[key]++;
} else {
map[key] = 1;
}
});
Demo: http://jsfiddle.net/Guffa/0a35c6yp/
You can convert your var with this code :
var arr = [ "1:R1", "2:R2", "3:R3", "4:R1" ];
var obj = {};
for(var i=0, l=arr.length; i<l; i++) {
var parts = arr[i].split(':');
if(parts.length > 1) {
if(!obj[parts[1]]) {
obj[parts[1]] = 0;
}
obj[parts[1]]++
}
}
console.log(obj)
Or create directly the correct object :
var obj = {};
$('input:checked').each(function (index) {
var key = $(this).val();
if (!obj[key]) {
obj[key] = 0;
}
obj[key]++
});
Use a regex to capture the correct portion of the string, and add them as keys to the object, incrementing the value if it already exists:
var regex = /\d+:(R\d+)/
var obj = {};
arr.forEach(function (el) {
var key = el.match(regex)[1];
if (!obj[key]) obj[key] = 0;
obj[key]++;
});
DEMO
You could try something like that:
Write your Array into a Map and step up your value each time your map already knows the key.
for(var i = 0; i < myArray.length; i++){
var entry = myArray[i];
var key = entry.split(":")[1];
if(myMap.has(key))
myMap.set(key, myMap.get(key) + 1);
else
myMap.set(key, 1);
}
DEMO
I have a JSON array which looks like this:
var map_results = [{"Type":"Flat","Price":100.9},
{"Type":"Room","Price":23.5},
{"Type":"Flat","Price":67.5},
{"Type":"Flat","Price":100.9}
{"Type":"Plot","Price":89.8}]
This array contains about 100,000 records. I want the output to be grouped by "Type" and "Price". It should look like this:
var expected_output = [{"Type":"Flat", "Data":[{"Price":100.9, "Total":2},
{"Price":67.5, "Total":1}] },
{"Type":"Room","Data":[{"Price":23.5,"Total":1}]},
{"Type":"Plot","Data":[{"Price":89.8, "Total:1"}]}]
This has to be done in pure javascript and I cannot use libraries like undersore.js. I tried solving the problem but it had like 3 nested for loops which made the complexity as n^4. What could be a better solution for this problem??
The function I have looks like this:
var reduce = function (map_results) {
var results = [];
for (var i in map_results) {
var type_found = 0;
for(var result in results){
if (map_results[i]["Type"] == results[result]["Type"]){
type_found = 1;
var price_found = 0;
for(var data in results[result]["Data"]){
if(map_results[i]["Price"] == results[result]["Data"][data]["Price"]){
price_found = 1;
results[result]["Data"][data]["Total"] +=1;
}
}
if(price_found == 0){
results[result]["Data"].push({"Price":map_results[i]["Price"], "Total":1});
}
}
}
if(type_found == 0){
results.push({"Type":map_results[i]["Type"], "Data":[{"Price":map_results[i]["Price"],"Total":1}]});
}
}
return results;
};
I have a short function that handles the first part of the requested functionality: It maps the map_results to the desired format:
var map_results = [{"Type":"Flat","Price":100.9},
{"Type":"Room","Price":23.5},
{"Type":"Flat","Price":67.5},
{"Type":"Flat","Price":100.9},
{"Type":"Plot","Price":89.8}]
var expected_output = map_results.reduce(function(obj, current){
if(!obj[current.Type]){
obj[current.Type] = {'Type':current.Type, 'Data':[]};
}
obj[current.Type].Data.push({'Price':current.Price, 'Total':1});
return obj;
},{})
Then this piece of code is required to calculate the totals, I'm afraid:
for(var type in expected_output){
var d = {};
for(var item in expected_output[type].Data){
d[expected_output[type].Data[item].Price] = (d[expected_output[type].Data[item].Price] || 0) + 1;
}
expected_output[type].Data = [];
for(var i in d){
expected_output[type].Data.push({
'Price':i,
'Total':d[i]
})
}
}
Output:
{
"Flat":{
"Type":"Flat",
"Data":[{"Price":"100.9","Total":2},
{"Price":"67.5","Total":1}]
},
"Room":{
"Type":"Room",
"Data":[{"Price":"23.5","Total":1}]
},
"Plot":{
"Type":"Plot",
"Data":[{"Price":"89.8","Total":1}]
}
}
As the Types and the Prices are unique after grouping I think a structure like {"Flat": {"100.9":2,"67.5":1}, {"Room": {"23.5": 1}}} would be easier to handle. So could do the grouping the following way:
var output = {};
map_results.map(function(el, i) {
output[el["Type"]] = output[el["Type"]] || [];
output[el["Type"]][el["Price"] = (output[el["Type"]][el["Price"]+1) || 1;
});
If you can not handle this structure you could do another mapping to your structure.
As you are iterating the Array one time this should have a complexity of n.
Look here for a working fiddle.
EDIT: So remap everything to your structure. The order of the remapping is far less then the first mapping, because the grouping is already done.
var expected_output = [];
for(type in output) {
var prices = [];
for(price in output[type]) {
prices.push({"Price": price, "Total": output[type][price]);
}
expected_output.push({"Type": type, "Data": prices});
}
Below is yet another effort. Here's a FIDDLE
For performance testing, I also mocked up a JSPerf test with 163840 elements. On Chrome(OSX) original solution is 90% slower than this one.
Few notes:
Feel free to optimize for your case (e.g. take out the hasOwnProperty check on object cloning).
Also, if you need the latest Total as the first element use unshift instead of push to add the obj the beginning of the array.
function groupBy(arr, key, key2) {
var retArr = [];
arr.reduce(function(previousValue, currentValue, index, array){
if(currentValue.hasOwnProperty(key)) {
var kVal = currentValue[key];
if(!previousValue.hasOwnProperty(kVal)) {
previousValue[kVal] = {};
retArr.push(previousValue[kVal]);
previousValue[kVal][key] = kVal;
previousValue[kVal]["Data"] = [];
}
var prevNode = previousValue[kVal];
if(currentValue.hasOwnProperty(key2)) {
var obj = {};
for(var k in currentValue) {
if(currentValue.hasOwnProperty(k) && k!=key)
obj[k] = currentValue[k];
}
obj["Total"] = prevNode["Data"].length + 1;
prevNode["Data"].push(obj);
}
}
return previousValue;
}, {});
return retArr;
}
var map_results = [{"Type":"Flat","Price":100.9},
{"Type":"Room","Price":23.5},
{"Type":"Flat","Price":67.5},
{"Type":"Flat","Price":100.9},
{"Type":"Plot","Price":89.8}];
var expected_output = groupBy(map_results, "Type", "Price");
console.dir(expected_output);
Tried something like this:
var reduce_func = function (previous, current) {
if(previous.length == 0){
previous.push({Type: current.Type, Data:[{Price:current.Price,Total:1}]});
return previous;
}
var type_found = 0;
for (var one in previous) {
if (current.Type == previous[one].Type){
type_found = 1;
var price_found = 0;
for(var data in previous[one].Data){
if(current.Price == previous[one].Data[data].Price){
price_found = 1;
previous[one].Data[data].Total += 1;
}
}
if(price_found == 0){
previous[one].Data.push({Price:current.Price, Total:1});
}
}
}
if(type_found == 0){
previous.push({Type:current.Type, Data:[{Price : current.Price ,Total:1}]});
}
return previous;
}
map_results.reduce(reduce_func,[]);