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I want to removeItem on localstorage but ı dont use localstorage.removeItem().Because ı want to delete a index in array(Sepet=array)
How can ı do it ?
thx
var array = [
{
'id': 1,
'name':'test1'
},
{
'id': 2,
'name':'test2'
},
{
'id': 3,
'name':'test3'
}
];
console.log(array);
localStorage.setItem('test', JSON.stringify(array));
var selected = 1;
var getArray = JSON.parse(localStorage.getItem('test'))
getArray.splice(selected,1);
localStorage.setItem('test', JSON.stringify(getArray));
console.log(getArray);
To get object from localStorage you need the Helper: localStorage.getItem('objectName');. You will get a string and not a object. To transform this string to a Object you need the function JSON.parse(string). And on this point you can work with the object. If you will delete item by index then remove it with object[index]and if you will remove item by value key like id: 2 then use JS Object function function like spliceto remove this item.
After that you have to stringify the object again to a string with JSON.stringify(object). This string you can store in the lcoalStorage withe the methode: localStorage.set(string)
That is the entire workflow.
localStorage is meant to store String values, so if you want to remove an item at a particular index, bear in mind that you need to convert the stringyfied array into plain JS array, then remove the item with array.slice(), and save the updated array back to localStorage.
You can checkh the Array.slice() documentation
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I have a function that returns the following:
{ 'random_string': '' }
Where random_string is an id that I do not know until it is returned.
How do I extract the value of random_string in JS? Thank you.
var a = { 'random_string': '' }
console.log(Object.keys(a)[0])
Your variable a has a value of type Object. Take a look at the Object prototype's documentation and see which methods are available to you: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object
You're trying to get your object's first key, and so conveniently you can use Object.keys as follows:
var a = { 'random_string': '' }
// Get array of Object's key values as strings
var aKeys = Object.keys(a);
console.log(aKeys);
// Print first key, in this case you only have one
console.log(aKeys[0]);
But based on your comments, you're going about this wrong.
If your "random_string" property identifier is truly random, you'd want to store the random string as an object property value.
That might look something like this:
// Generate some random string value
var random = Math.random().toString(36).substring(7);
// Create an object with a predefined object property identifier
var data = { 'random_value': random };
// Access the random value using your known property identifier
console.log(data.random_value);
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As the title suggests, how do I make a new object containing the 7 first keys of another object using JS? :) This is the structure of the object I would like to copy the data from.
{"data":[{"id":2338785,"team1":{"id":10531,"name":"Just For Fun"},"team2":{"id":10017,"name":"Rugratz"},"result":"2 - 0","event":{"name":"Mythic Cup 5","id":5148},"format":"bo3","stars":0,"date":1578279271000},....],"last_update":1578329378792}
Let's say there are 100 keys like this one, and I only want to copy the 7 first ones into a new object in JS.
Well technically, you have only 2 keys in the given Object but if you mean the data object, here's what you can do.
const MyNewObject = Object.entries(YourObject)
const results = []
and a simple for loop
MyNewObject.forEach((pair,i) => {
// for the 8th item it breaks and doesn't push it to results array
if ( i === 7 ) break;
results.push(pair)
}
OR u use slice instead :
// a little bit neater , and u call remove the empty results array above
const thisNewResult = MyNewObject.slice(0,6)
and finally the results is an array of key value pairs and you should do this code to make a new object from the results entries
const finalResults = Object.fromEntries(results)
Please notice that this may not be the Order you want since Object.Entries gives you the same order as the order of for in loop (for more info visit Elements order in a "for (… in …)" loop)
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Instead of using associative arrays (objects), what is the best way to associate two values so they are always associated and can both be accessed as separate values? Associative arrays are annoying because their order isn't guaranteed and you can't access them using indexes.
I could create two separate arrays but if I randomize their order for display their association would not match, and if they are separate in code there is a good chance I can make a mistake when recording their values, putting them in the wrong order so they don't perfectly match up.
In Javascript you can use multidimensional arrays:
var data = [
[1, 2],
[3, 4]
];
data[0][0]; // get '1'
data[0][1]; // get '2'
Also if you need to associate data in a more abstract way, ES6 has WeakMaps:
var wm = new WeakMap();
var x = document.createElement("div");
wm.set(x, {foo: 1, bar: 7});
console.log(wm.get(x).bar) // get '7' from object you associated to HTMLElement
I do not now which kind of data you should store but maybe you could try to store data in a single variable in this way:
var data = [];
data[0] = "Test" + "|" + Value;
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Each ArrayItem contains no. of Property like Id, Name, Description etc
But we want to Fetch ArrayItem with Help of Name Property .
So Please give me code suggestion in Jquery or backbonejs without using for loop.
If you are using BackboneJS, you already have UnderscoreJS installed. Underscore has several methods for searching through a collection. For instance, using _.findWhere(...):
var myArray = [ ... ];
var helpItem = _.findWhere(myArray, { name: 'help' });
This would return the first entry in the array that has a name property equal to 'help'. _.findWhere(...) can match multiple properties too. If you want to find an item with something other than direct equality of properties, you can use _.find(...):
var overTwentyOne = _.find(myArray, function(entry) {
return entry.age > 21;
});
This would return the first entry in the array whose age property was greater than 21.
Note also that most of the list-centric methods in Underscore are automatically mixed into all Backbone.Collection instances. So if you were searching through a Collection, the above findWhere(...) example could be more simply written as:
var helpItem = collection.findWhere({ name: 'help'});
This would return the first Backbone.Model instance from collection that had a property name equal to help.
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I had a object object array which i used JSON.stringify() on i can now see what's in my array but when i do arr[0] etc it only outputs one letter.
arr = {"hello":"yes","because":"no"}
arr[0] =h
I want it to output the whole of the value not just the first letter
My code
var clientContext = SP.ClientContext.get_current();
var peopleManager = new SP.UserProfiles.PeopleManager(clientContext);
// Get user properties for the target user.
// To get the PersonProperties object for the current user, use the
// getMyProperties method.
MyProperties = peopleManager.getMyProperties();
// Load the PersonProperties object and send the request.
clientContext.load(MyProperties);
clientContext.executeQueryAsync(getMyNewsChoicesSuccess, getMyNewsChoicesFail);
},
getMyNewsChoicesSuccess = function () {
//get the news choice by actually fieldname
var MyChoices = JSON.stringify(MyProperties.get_userProfileProperties().Value);
$('#NBStest').text(MyChoices);
},
You can get the first element from your json string like this
JSON.parse(json_str)[0]
but in the example you have, the first element is "yes" and its index is "hello" , which means you can't get the first element by the index 0 , however you can get it by its property name like this
arr.hello = "yes";
// or
arr['hello'] = "yes";
if you want to get the hello which is the key , you have to use this loop
for (key in arr)
console.log(key);
// it will print 'hello' and then 'because'
Well its not an array anymore, its a string. arr[0] will return the first letter.
If you want to get the objects from it you need to parse it ( try JSON.parse )
JSON.stringify() does exactly what it sounds like. It turns the javascript object into a string. So when you do arr[0] you are getting the first letter in the string. You need to turn it back into a javascript object if you want to get the actual values.