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Combining two arrays into an object

I have two arrays one with label date i.e [Date, Date, Date ...] and
the other with the actual date data i.e [2021-11-26, 2021-11-25, ...].
I want to combine these two arrays such that I get array of objects such as [ { Date: 2021-11-26}, {Date:2021-11-25}, {..}, ...].
I have tried these two methods
obj = {};
for (var i = 0, l = date_label.length; i < l; i += 1) {
obj[date_label[i]] = data_date[i]
}
console.log(obj);
and
_.zipObject(date_label, data_date);
However it only ends up giving me the last date of my data set, in an object data structure ie { Date: 1999-11-24}

The keys inside an object / associative array are unique. Your obj is such a thing. If you turn it into a regular array and push new objects into it, it will work.
const obj = [];
for (let i = 0, l = date_label.length; i < l; i++) {
obj.push({[date_label[i]]: data_date[i]})
}
console.log(obj);
You should probably assert that both your arrays have the same length.

The issues you are facing is that your date_label are the same and the loop are replacing the dates on the same label, again and again, you just need to change the label name and give unique to each one or you change them into the loop as well like this (obj[date_label[i] + str(i)] = data_date[i]).
date_label = ['date1', 'date2', 'date3', .....]
obj = {};
for (var i = 0, l = date_label.length; i < l; i += 1) {
obj[date_label[i]] = data_date[i]
}
console.log(obj);

obj is of type array not object.
data_date needs to be in string format.
for(var i= 0; i<data_date.length-1;i++) {
obj.push({"Date":date_date[i]}) }

with array reduce
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce
var myFinalArray = data_date.reduce(
(previousValue, currentValue, currentIndex, array) => ({
currentValue: date_label[currentIndex]
}), {});

Hello AshleyCrasto,
Welcome to Stackoverflow.
Sol : Well, the other members have given solution on how to achieve the desired result. I will emphasize on why you are getting the single object.
it only ends up giving me the last date of my data set, in an object data structure ie { Date: 1999-11-24}
You need to understand how references work in JavaScript. Heres the catch,
As the values in date_label are all same
[Date, Date, Date ...]
When you use,
obj[date_label[i]] = data_date[i]
Everytime, it get executed the same key value will be keep updating instead of creating new key and new value. Because the same values holds same reference.
So, first time {"date" : "somevalue"} will be there, then
second time {"date" : "somevalue2"}, the value of key "date" will be updated
with new value. This is due to same key.
Therefore, you need to take of this thing. For your better understanding here is my code: (same as others but elaborately)
const date_label = ["date","date"]
const data_date = [2021-11-26, 2021-11-25]
function returnObj(label, value){
//this will return a new object with provided label and value.
const Obj = {};
Obj[label] = value
return Obj
}
let listOfObjects = []
for(let i=0 ; i< date_label.length ; i++){
//new object will be added to list.
const obj = returnObj(date_label[i],data_date[i])
listOfObjects.push(obj)
}
console.log(listOfObjects)

How to remove double quotes from json array in javascript

I have a array :
Var array=[{"name":"May","data1":"1121.0"}]
I want to change it to :
Var array= [{"name":"May","data1":1121.0}]

You can simply check using Number.isNaN with an attempted cast to a number using the + operator. If it returns true then do nothing. If it's false then change the value of the parameter to a cast number.
var array=[{"name":"May","data1":"1121.0"}];
array.forEach(data => {
for(let key in data) Number.isNaN(+data[key]) || (data[key] = +data[key])
});
console.log(array);

Looks like this has been answered before here
I'll summarize;
for(var i = 0; i < objects.length; i++){
var obj = objects[i];
for(var prop in obj){
if(obj.hasOwnProperty(prop) && obj[prop] !== null && !isNaN(obj[prop])){
obj[prop] = +obj[prop];
}
}
}
console.log(JSON.stringify(objects, null, 2));
This does have a bug where 0 becomes null.

You want to convert the value mapped to the "data1" key to be a number instead of a string.
There are many ways to accomplish this in JavaScript, but the best way to do so would be to use Number.parseFloat like so:
var array = [{"name":"May","data1":"1121.0"}];
array[0]["data1"] = Number.parseFloat(array[0]["data1"]);
console.log(array[0]["data1"]); // 1121
If you need to perform this action with multiple objects inside of array, you could do
var array = [{"name":"May","data1":"1121.0"}, {"name":"May","data1":"1532.0"}, etc.] // Note that this is not valid JavaScript
array.map(obj => {obj["data1"] = Number.parseFloat(obj["data1"]); return obj;});

If I understood well, you only want to convert the value of data1, from "1121.0" to 1121.0, in other words from string to number.
To convert only that key (data1), you only need this:
array[0].data1 = parseFloat(array[0].data1)
If that's not what you want, please explain better your question

getting index of string in array

I'm bashing my head over this one. I have tried using indexOf() and made my own function to iterate through the array and compare each term but I am always getting -1!
function checkindex(array,temp) {
for(var i = 0; i < array.length; i++) {
console.log(array[i] + " " + temp);
if (array[i] == temp) return i;
}
return -1;
}
array is an Object which is generated this way:
var array = (req.body.somestring).split(',');
When I output array and string this way:
console.log(array[i] + " " + temp);
I get something like this:
["My variable","Something else"] My variable
The spelling matches but its still -1. array.indexOf(temp) gives me the same results. Any thoughts?
Thanks in advance.

This seems to work for me:
var array = ["My variable","Something else"];
var lookup = "My variable";
var index = array.indexOf(lookup);
alert(index);
There is a nice polyfill for older browsers that can be found here:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf

So the problem was actually more upstream... I stringified the data (JSON.stringify) prior to sending it so the string from var array = (req.body.somestring).split(','); included brackets and all. That why the output of console.log(array) looked like this:
["My variable","Something else"]
The elements in this situation are:
array[0] === ["My variable"
array[1] === "Something else"]
The solution was instead of split was use JSON.parse. The output of console.log(array) after that was:
My variable,Something else
Thank you for your help.

Stringify an JS Object in Asc order

I have an js object like
{
a: 1,
b: 2,
c: 3
}
I wanted to stringify the above object using JSON.stringify with the same order. That means, the stringify should return me the strings as below,
"{"a":"1", "b":"2", "c":"3"}"
But it is returning me like the below one if my js object has too many properties say more than 500,
"{"b":"2", "a":"1", "c":"3"}"
Is there any option to get my js object's json string as in sorted in asc.

If the order is important for you, don't use JSON.stringify because the order is not safe using it, you can create your JSON stringify using javascript, to deal with string values we have 2 different ways, first to do it using regexp an replace invalid characters or using JSON.stringify for our values, for instance if we have a string like 'abc\d"efg', we can simply get the proper result JSON.stringify('abc\d"efg'), because the whole idea of this function is to stringify in a right order:
function sort_stringify(obj){
var sortedKeys = Object.keys(obj).sort();
var arr = [];
for(var i=0;i<sortedKeys.length;i++){
var key = sortedKeys[i];
var value = obj[key];
key = JSON.stringify(key);
value = JSON.stringify(value);
arr.push(key + ':' + value);
}
return "{" + arr.join(",\n\r") + "}";
}
var jsonString = sort_stringify(yourObj);
If we wanted to do this not using JSON.stringify to parse the keys and values, the solution would be like:
function sort_stringify(obj){
var sortedKeys = Object.keys(obj).sort();
var arr = [];
for(var i=0;i<sortedKeys.length;i++){
var key = sortedKeys[i];
var value = obj[key];
key = key.replace(/"/g, '\\"');
if(typeof value != "object")
value = value.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
arr.push('"' + key + '":"' + value + '"');
}
return "{" + arr.join(",\n\r") + "}";
}

The JavaScript objects are unordered by definition (you may refer to ECMAScript Language Specification under section 8.6, click here for details ).
The language specification doesn't even guarantee that, if you iterate over the properties of an object twice in succession, they'll come out in the same order the second time.
If you still required sorting, convert the object into Array apply any sorting algorithm on it and then do JSON.stringify() on sorted array.
Lets have an example below as:
var data = {
one: {
rank: 5
},
two: {
rank: 2
},
three: {
rank: 8
}
};
var arr = [];
Push into array and apply sort on it as :
var mappedHash = Object.keys( data ).sort(function( a, b ) {
return data[ a ].rank - data[ b ].rank;
}).map(function( sortedKey ) {
return data[ sortedKey ];
});
And then apply JSON.stringy :
var expectedJSON = JSON.stringify(mappedHash);
The output will be:
"[{"rank":2},{"rank":5},{"rank":8}]"

JavaScript Array / Struct

I would like to create a structure within javascript. I have a pair of informations, I would like to use, example:
array[1] = new Struct();
array[1].name = "parameter-name";
array[1].value = "parameter-value";
array[2] = new Struct();
array[2].name = "parameter-name2";
array[2].value = "parameter-value2";
This can be on a diffrent page with diffrent values, maybe on element within my array, maybe 2-20..
Later, within my generic javascript, I would like to parse the array and continue with my parameters, example:
for(i=1 to length_of_my_array) {
_tag.array[i].name = array[i].value;
}
How can I realize this with pure javascript? Thanks for any hint!

As long as you don't want any fancy features, it's really easy to create such structures in JavaScript. In fact, the code you posted will almost work, if you replace the new Struct() with this:
array[1] = {};
This creates an empty object, and you can put any properties you want in it, such as name and value.
To create an array, you can do something like this:
var array = []; // empty array
// object literal notation to create your structures
array.push({ name: 'abc', value: 'def' });
array.push({ name: 'ghi', value: 'jkl' });
...
And to iterate over the array:
for (var i = 0; i < array.length; i++) {
// use array[i] here
}

It would be good to find out more regarding the problem you are attempting to resolve.
I don't think there is an object in JavaScript called Struct, unless you define one.
I think what you are looking for is a JavaScript object instead of Struct. There are a number of ways to create a new object, and they can be nested in an array or in other objects.
myArray[0] = new Object();
myArray[0].name = "parameter-name";
myArray[0].value = "parameter-value";
myArray[1] = new Object();
myArray[1].name = "parameter-name2";
myArray[1].value = "parameter-value2";
Notice that I have changed your code in a couple of ways:
1. "array" is named "myArray" to clarify that we are referring to a particular array.
2. The first instance of myArray is 0. Arrays start at 0 in Javascript.
3. Struct is changed to Object.
myarray = [
{
"name":"parameter-name",
"value":"parameter-value"
},
{
"name":"parameter-name2",
"value":"parameter-value2"
}
];
This is an alternative syntax for doing the same thing. It uses "literal notation" to designate an array (the square brackets), and the objects (the curly brackets).
for(var i = 0; i < myArray.length; i++) {
for(key in myArray[i]) {
alert(key + " :: " myArray[i][key]);
}
}
This will loop over the array and alert you for each property of the object.
alert(myArray[0]['value']) //parameter-value
myArray[0]['value'] = "bar";
alert(myArray[0]['value']) //bar
Each property of each object can also be assigned a new value.

You can define arrays and generic objects in pure JavaScript/json:
var array = []; // empty array
array.push({name: 'parameter-name', value: 'parameter-value'});
array.push({name: 'parameter-name2', value: 'parameter-value2'});
console.log(array);
// Output:
// [Object { name="parameter-name", value="parameter-value2"}, Object { name="parameter-name2", value="parameter-value2"}]
You can also define the same array like so:
var array = [
{name: 'parameter-name', value: 'parameter-value'},
{name: 'parameter-name2', value: 'parameter-value2'}
];
As far as looping through the array:
for (var i = 0; i<array.length; i++) {
var elem = array[i];
console.log(elem.name, elem.value);
}
// Outputs:
// parameter-name parameter-value2
// parameter-name2 parameter-value2

I'd store object literals in the array, like so:
var myArray = [];
myArray[0] = {name:"some name", value:"some value"};
myArray[1] = {name:"another name", value:"another value"};
for (i=0; i < myArray.length; i++) {
console.log(myArray[i].name + ' / ' + myArray[i].value);
}

// initialize empty array
var myArray = [];
// fill it with an object - the equivalent of a struct in javascript
myArray.push({
name: 'example-name'
value: 'example-value'
});
// repeat as neccessary
// walking through the array
for (var i = 0; i < myArray.length; i++)
{
// retrieving the record
record = myArray[i];
// and accessing a field
doSomething(record.name);
}

var array = {paramName: 'paramValue', paramName2: 'paramValue2'};
for(i in array) {
_tag.i = array.i;
}

There is no "Struct" in JavaScript only Object
my_array = new Array();
my_array.push({name: 'john', age:31});
my_array.push({name: 'da_didi', age:120});
for (i=0; i<my_array.length; i++)
{
alert(my_array[i].name);
}

How about
function Struct(name, value) {
this.name = name;
this.value = value;
}
arr[0] = new Struct("name1", "value1");

Javascript objects are loose objects: properties can be added and removed dynamically. So making a new Struct(), as you suggest, does -not- guarantee that the returned object will always have the properties you expect it to have. You have to check the availability of properties at the point of usage (duck typing):
var i, element;
for (i = 0; i < array.length; i++) {
element = array[i];
if (Object.hasOwnProperty.call(element, "name")
&& Object.hasOwnProperty.call(element, "value")) {
_tag[element.name] = element.value;
}
}
(Also, I'm just guessing that _tag is an object itself, but that wasn't clear from your example.)
You could probably use a more succinct syntax, but that depends heavily on the values of the properties. For example, you -might- be able to use something like this:
var i, element;
for (i = 0; i < array.length; i++) {
element = array[i];
if (element.name && element.value) {
_tag[element.name] = element.value;
}
}
But you need to realize that the above condition will be false not only if one or both of the properties (name and value) are undefined but also if the value of either or both refers to the empty string, null, 0, NaN, or false.