I'm trying to convert an Object array into an array without use "let item of array" on html, I already google a lot but nothing that I find works.
Why I don't use loops? because I pretend to display data inside a page that comes from a liteSQL database, so all the data that I extract from that it's an Object and sure I can display the data without issues if I use a loop like "let item of array" but in this case I just want to show information on the HTML like item.name or item.avatar
Thanks in advance for any help, If you guys need more information please let me know.
The database have students so every array have: name, age, avatar, etc, so I try to show some like a profile after they tap the name on the list
EDIT:
What you are receiving from your server is an array of objects.
array of objects ->
[{
key1:vlaue1,
key2:value2
},
{
key1:vlaue1,
key2:value2
}]
You refer the values here by using array[0]['key1'] array[0]['key2'] and so on
In your case, you are receiving only one object in the array, so simply use array[0].name array[0].age and so on
Thanks for the help, I actually found the solution by my self, I just need to use:
item: array = <array>{};
in order to use my object array as a simple array items without any loop on html
Related
I have some problems mapping an array of objects in JS.
This is how the response looks in my console:
[{...}]
...and when I expand it I get this:
0:{id:0, document:{...}}
1:{id:1, document:{...}}
Usually the response I get is always without this number in front of each object, like this:
{id:0, document:{...}
{id:1, document:{...}
I tried every approach I know and I cant't manage to handle it.
The goal is to take each value out of "document" property and dynamically display it in some kind of table.
This is the way the browser devtools decides to display the array, but it is actually correct, if I'm not mistaken you're still dealing with an array.
You can verify this by logging the following:
(Replace myVar with the variable name you chose for your response array)
console.log(Array.isArray(myVar))
If it outputs true then you're fine and you are dealing with an array.
I'm making a scheduling app, and storing all the scheduled things in firebase with arrays. When I try to schedule something with the same string value, it fails and doesn't add it to the array. I don't know if this is something in swift I can edit, or if it's a firebase setting.
If it's something in swift, here's the code updating the array:
doc.updateData([
"Instructor": FieldValue.arrayUnion(["\(scheduleinstructor)"])
])
If it's something in firebase, could someone please explain a way around this or a simple fix I overlooked?
According to the documentation on adding items to an array:
arrayUnion() adds elements to an array but only elements not already present
So the fact that the duplicate entry is not added is by design. If you want to allow that, you'll have to:
Read the document with the array from the databae.
Extract the array from the document into your application code.
Add the item to the array.
Write the entire modified array back to the database.
If I would like to match the word that I need to find it the same as <lookup> in Excel. I intend to create a form for Example. I have a file certain big data and I will create a box for fill in data that you need then Enter it show the Description of data. Now I got stuck I don't know how to write to the script I have learned in youtube but don't have a solution that nearby with my need it nearby just <Indexof> function.
var data = Activesheet.getRange(1,1,Activesheet.getLastRow()-1,1).getValues();
Logger.log(data.indexOf("TPBSA"));
data is a 2D(two dimensional) array. indexOf only works with a 1D array. flatten the array before indexOf:
const data = [["A1"],["A2"],["TPBSA"],["A4"]];
console.info(data.flat().indexOf("TPBSA"));
//or
console.info(data.findIndex(e=>e[0]==='TPBSA'))
I'm using React Native and Open Weather Map API to build a small weather app. The data I retrieve from the API call is more than I want to use so I parse out just the pieces I need and store them in an array. I then take the array and set it to a state object. I can reference the object, but instead of saying my array is an array, it says it's an object, and thus won't let me use any array methods on it. How do I get around this?
//reponseData is the data retrieved from the API call; the data retrieved is an object with arrays and objects
within. The forecast data for the next five days is given in 3 hour increments, so you have a 40 item array of
data pieces. I loop through this list of 40 items, pull out just what I need...
let forecastArray = [];
for (let i=0; i<responseData.list.length; i++) {
let day = responseData.list[i].date
let high = responseData.list[i].weather[0].hiTemp
let low = responseData.list[i].weather[0].loTemp
let condition = responseData.list[i].sys.condition
forecastArray.push(day)
forecastArray.push(high)
forecastArray.push(low)
forecastArray.push(condition)
this.setState({
forecastData: forecastArray
})
When I log, I get an array....
console.warn("forecast is: ", this.state.forecastData)
OUTPUTS: forecast is: ["11-06-2019", 52.5, 47.3, "sunny", "11-06-2019", 63.9, 39.7, "sunny", ...]
Referencing this.state.forecastData[2], for example, however was giving me errors. So I checked the typeof this.state.forecast to see why and it says the array is an Object? I need to further divide out the array data and manipulate it. The first several items (e.x. forecastData[0] through forecastData[9] would be for the forecasted weather for 11-06-2019 at 3pm, ,6pm, 9pm so I need to pull those items, get the highest high and lowest low, etc. I can't do that since I can't even reference the items in the array.
Things I've tried:
using Object.entries and Object.assign methods, but that just splits the items into several arrays, with the first item being the location number and the second item being the array item content. I've tried manipulating the array within the component that uses it, but it still is an Object not an Array, so I can't reference the individual items. The data set is large enough I don't think it would be best practice to push each of the 40+ items into their own state object key.
in Javascript array is a subset of object , i'e it has the same prototype. So typeof Array will be an object. Thats not an issue. Can you update with the error which you are getting while accessing this.state.forecastData[2] coz what i . believe its something not with syntax , rather with the duration of API call.
I would recommend when accessing this.state.forecastData[2] first check if its length is greater than 0 , that way you are sure that there is data inside the array.
constructor(props){
forecastData:[]
}
and when you use it ,
if(this.state.forecastData.length > 0){
this.state.forecastData[2]
}
Try this, and revert with doubts.
Thank you, Gaurav Roy! You were partly correct. The typeof didn't matter at all. But the issue wasn't with the duration of my API, it was that my component was trying to render when it didn't have the data from the API call yet! I put in a conditional
{this.state.forecast !== null && <Forecast forecast=this.state.forecastData />}
and got things working now. Thanks for the quick reply!
I am retrieving specific data as an array from firestore, the value is the there on the console.log(), but i cant seems to retrieve the specific data from the array itself,
here's my event.ts
import { Event } from '../../models/event';
invitedEvents: Event[] = [];
this.invitedEvents = invitedEvents;
console.log(invitedEvents, invitedEvents.name);
on console.log()
as you can see the invitedEvents.name return value of undefined, i'm sure you guys know the proper way of retrieving the value of name, send help.
The object is in the array, so you have to access object from array first invitedEvents[0]
console.log(invitedEvents, invitedEvents[0].name);
Here you have to invitedEvents is an array. So if you need to access you can't directly like invitedEvents.name like this, here is the few ways to access.
for(let item of invitedEvents){
console.log("Data",item);
console.log("Specific Name",item.name);
}
This example is used to print multiple values.
If you have only one value.Simply do like this.
console.log("Specific Name Second way", invitedEvents[0].name);
I hope its helps you.
Thanks,
Muthu