JavaScript function to create a structured Object from a String? - javascript

Could someone help me to create a JavaScript function that would turn the string below into an Object?
var structure = 'user.location.city';
When ran through the JavaScript function would return an object structured like this:
user: {
location: {
city: {}
}
}
I came up with the code below, but the object is messed up:
var path = structure.split('.');
var tmp_obj = {};
for ( var x = 1; x < path.length; x++ ) {
tmp_obj[path[x]] = {};
};
I don't know how to add the "city" Object to the "location" Object.


var path = structure.split('.');
var tmp_obj = {};
var obj = tmp_obj;
for(var x = 1; x < path.length; x++) {
tmp_obj[path[x]] = {};
tmp_obj = tmp_obj[path[x]];
};

Related

Defining a 3D array in JavaScript

I tried to define a 3D array on Google Sheet, but even though I'm using the .slice() method it keeps passing the array by reference.
var temp = [];
for (var a = 0; a<archetypesAll.length; a++) {temp[a] = [0, a].slice();};
var archRank = [];
for (var a = 0; a<21; a++) {archRank[a]= temp.slice();};
archRank[2][1][0] = 'Test';
I want to edit a single element of the matrix but instead the code above just fills every row with the exact same value ('Test'):
3DMatrix[x][1][0] = 'Test'

You can't just copy a multidimensional array by calling slice at the top level, because that will not deep-copy the whole. You have to write your own deepCopy methid, like this:
function allocate(mainDim, ...dims) {
const result = new Array(mainDim);
for (let i = 0; i < result.length; i++) {
result[i] = dims.length > 0 ? allocate(...dims) : 0;
}
return result;
}
function deepCopy(matrix, dims) {
return dims > 1 ? matrix.map(row => deepCopy(row, dims - 1)) : matrix.slice();
}
function test() {
const mx1 = allocate(3,2,2);
mx1[2][1][0] = "Test";
console.log(JSON.stringify(mx1));
const mx2 = deepCopy(mx1, 3);
mx2[2][1][0] = "Copied";
console.log(JSON.stringify(mx1));
console.log(JSON.stringify(mx2));
}
test();

var array = ["Test", "Test"];
var array3d = [[array.slice(0)],[[array.slice(0)]]];
array3d[0][0][0] = "Changed";
console.log(JSON.stringify(array3d)); //[[["Changed","Test"]],[[["Test","Test"]]]]
Try with this instead of slice to get a new array instead of reference:
var temp = [];
for (var a = 0; a < archetypesAll.length; a++) {
temp[a] = JSON.parse(JSON.stringify([0, a]));
}
var archRank = [];
for (var a = 0; a < 21; a++) {
archRank[a]= temp.slice();
}
archRank[2][1][0] = 'Test';

Alternately Join 2 strings - Javascript

I have 2 strings and I need to construct the below result (could be JSON):
indexLine: "id,first,last,email\n"
dataLine: "555,John,Doe,jd#gmail.com"
Result: "id:555,first:john,....;
What would be the fastest way of joining alternately those 2 strings?
I wrote this - but it seems too straight forward:
function convertToObject(indexLine, dataLine) {
var obj = {};
var result = "";
for (var j = 0; j < dataLine.length; j++) {
obj[indexLine[j]] = dataLine[j]; /// add property to object
}
return JSON.stringify(obj); //-> String format;
}
Thanks.

var indexLine = "id,first,last,email";
var dataLine = "555,John,Doe,jd#gmail.com";
var indexes = indexLine.split(',');
var data = dataLine.split(',');
var result = [];
indexes.forEach(function (index, i) {
result.push(index + ':' + data[i]);
});
console.log(result.join(',')); // Outputs: id:555,first:John,last:Doe,email:jd#gmail.com

If you might have more than one instance of your object to create, you could use this code.
var newarray = [],
thing;
for(var y = 0; y < rows.length; y++){
thing = {};
for(var i = 0; i < columns.length; i++){
thing[columns[i]] = rows[y][i];
}
newarray.push(thing)
}
source

make variable from variable javascript

i am trying to add data to an array where part of the array name is a variable.
if that makes sense?
this is my coding, i think its something to do with the ["charts"[d]] part but nothing is being added to the arrays
var
charts0 = [],
charts1 = [],
charts2 = [],
charts3 = []
var newdata = data.split("|");
var newdates = dates.split(",");
for (i = 0; i < newdates.length; i++) {
for (d = 0; d < newdata.length; d++) {
var dataparts = newdata[d].split(",");
["charts"[d]].push({x: newdates[i], y: dataparts[i+1]});
}
}

Use an object literal as an associative array.
var charts = {
charts0: [],
charts1: []
};
/* ... */
charts['charts' + d].push( // ...
But if you are going to do this, you could simply use an array, where the indices are implicit:
var charts = [[],[]];
/* ... */
charts[d].push( // ...

Create a new object with your arrays like
var ch = {
charts0: [],
charts1: [],
charts2: [],
charts3: []
}
Then you'll be able to do ch["charts" + d][i] etc..

The way you are doing it right now is not possible (without using eval, which you shouldn't). You can however add an extra 'layer' with your variables by using an object. Like so:
var myData = {
charts0: [],
charts1: []
charts2: []
charts3: []
};
var newdata = data.split("|");
var newdates = dates.split(",");
for (i = 0; i < newdates.length; i++) {
for (d = 0; d < newdata.length; d++) {
var dataparts = newdata[d].split(",");
myData['charts' + d].push({x: newdates[i], y: dataparts[i+1]});
}
}

Parsing Json Array Object in specific format in javascript

My JSON is:
var json = '{"name":"GeoFence","coordinate":[[1,2],[3,4],[5,6]]}',
obj = JSON.parse(json);
alert(obj.coordinate);
But i need to set the values of coordinates as follows:
var myTrip=[new google.maps.LatLng(1,2),new google.maps.LatLng(3,4),new google.maps.LatLng(5,6)];

Traverse the coordinates and create a new object for each, and add that to myTrip:
var myTrip = [];
for(var i=0; i < obj.coordinate.length; i++) {
myTrip.push(new google.maps.LatLng(obj.coordinate[i][0],obj.coordinate[i][1]))
}

How about this:
var json = '{"name":"GeoFence","coordinate":[[1,2],[3,4],[5,6]]}',
var obj = JSON.parse(json);
var myTrip = [];
for (var i = 0; i < obj.coordinate.length; i++) {
myTrip[i] = new google.maps.LatLng(obj.coordinate[i][0], obj.coordinate[i][1]);
}

You need to iterate over the collection of the coordinates:
var myTrip = getCoordinate ();
var getCoordinate = function(){
var ret = [];
for(var i = 0, length = coordinate.length; i < length; i++){
ret.push(new google.maps.LatLng(coordinate[i][0], coordinate[i][1]))
}
return ret;
}

how can I parse json with multiple lines

I have the following JSON:
[{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557704","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557705","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557706","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557707","mobile":"400089151"}]
I need to extract all "phoneNumber" using a js function.
I'm testing from using html and my function is not so good:
function getNumbers(strJSON)
{
strJSON = "[{\"errorMessage\":\"success\",\"mobile\":\"400089151\",\"phoneNumber\":\"400557704\",\"returnCode\":\"0\"},{\"errorMessage\":\"success\",\"mobile\":\"400089151\",\"phoneNumber\":\"400557705\",\"returnCode\":\"0\"},{\"errorMessage\":\"success\",\"mobile\":\"400089151\",\"phoneNumber\":\"400557706\",\"returnCode\":\"0\"}]";
var len = strJSON.length;
var begin_index = strJSON.indexOf("returnCode") - 2;
var last_index = len - 1;
var string_toSplit = strJSON.substring(begin_index, last_index);
var string_splitted = string_toSplit.split("{");
var out="";
alert(strJSON);
alert("string_splitted");
alert(string_splitted);
for ( var i = 0; i < string_splitted.length; i++)
{
if (string_splitted[i].charAt(string_splitted[i].length - 1) === ",")
{
string_splitted[i] = string_splitted[i].slice(0, -1);
}
var json = "{" + string_splitted[i];
var obj = JSON.parse(json);
if (i == string_splitted.length)
{
out = out + obj.phoneNumber;
}
else
{
out = out + obj.phoneNumber + ",";
}
}
return out;
}

For modern browsers you can use the .map() method
var j = [{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557704","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557705","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557706","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557707","mobile":"400089151"}];
var phones = j.map(function(item){return item.phoneNumber});
Update
After seeing your code (do not try to manually split/parse the json string.. use the JSON.parse method) you should use
function getNumbers(strJSON)
{
var myJson = JSON.parse( strJSON );
return myJson.map(function( item ){ return item.phoneNumber}).join(',');
}

Update: An even better way:
function getNumbers(strJSON)
{
var obj = JSON.parse(strJSON);
return obj.map(x => x.phoneNumber).join(", ")
}
Original Post:
A straight forward method is to just iterate over every object in the array and take the values out individually.
var info = [{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557704","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557705","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557706","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557707","mobile":"400089151"}];
var phoneNumbers = [];
for (var i = 0; i < info.length; i++)
{
phoneNumbers.push(info[i].phoneNumber);
}
console.log(phoneNumbers);
http://jsfiddle.net/hX69r/
UPDATE:
http://jsfiddle.net/hX69r/1/
var info = [{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557704","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557705","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557706","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557707","mobile":"400089151"}];
var infoString = JSON.stringify(info); //this just turns the object array 'info' into a string
var numbers = getNumbers(infoString);
console.log(numbers);
function getNumbers(strJSON)
{
var obj = JSON.parse(strJSON);
var phoneNumbers = [];
for (var i = 0; i < obj.length; i++)
{
phoneNumbers.push(obj[i].phoneNumber);
}
return phoneNumbers.join(", ");
}
Additional Update:
var info = [{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557704","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557705","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557706","mobile":"400089151"},
{"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557707","mobile":"400089151"}];
var infoSingle = {"returnCode":"0","errorMessage":"success","Code":{},"phoneNumber":"400557704","mobile":"400089151"};
console.log(info.length); // prints 4; so you know it has the []
console.log(infoSingle.length); // prints undefined; so you know it doesn't have []

Do not try to re-invent the wheel.
There are many ways to parse JSON already:
Use JSON.parse.
Use jQuery.parseJSON

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