Updating a JSON object using Javascript
JavascriptJqueryJsonJavascript Problem Overview
How can i update the following JSON object dynamically using javascript or Jquery?
var jsonObj = [{'Id':'1','Username':'Ray','FatherName':'Thompson'}, {'Id':'2','Username':'Steve','FatherName':'Johnson'}, {'Id':'3','Username':'Albert','FatherName':'Einstein'}]
I would like to dynamically update the Username to 'Thomas' where the 'Id' is '3'.
How can I acheive this?
Javascript Solutions
Solution 1 - Javascript
A plain JavaScript solution, assuming jsonObj already contains JSON:
Loop over it looking for the matching Id, set the corresponding Username, and break from the loop after the matched item has been modified:
for (var i = 0; i < jsonObj.length; i++) {
if (jsonObj[i].Id === 3) {
jsonObj[i].Username = "Thomas";
break;
}
}
Here's the same thing wrapped in a function:
function setUsername(id, newUsername) {
for (var i = 0; i < jsonObj.length; i++) {
if (jsonObj[i].Id === id) {
jsonObj[i].Username = newUsername;
return;
}
}
}
// Call as
setUsername(3, "Thomas");
Solution 2 - Javascript
simply iterate over the list then check the properties of each object.
for (var i = 0; i < jsonObj.length; ++i) {
if (jsonObj[i]['Id'] === '3') {
jsonObj[i]['Username'] = 'Thomas';
}
}
Solution 3 - Javascript
$(document).ready(function(){
var jsonObj = [{'Id':'1','Username':'Ray','FatherName':'Thompson'},
{'Id':'2','Username':'Steve','FatherName':'Johnson'},
{'Id':'3','Username':'Albert','FatherName':'Einstein'}];
$.each(jsonObj,function(i,v){
if (v.Id == 3) {
v.Username = "Thomas";
return false;
}
});
alert("New Username: " + jsonObj[2].Username);
});
Solution 4 - Javascript
use:
var parsedobj = jQuery.parseJSON( jsonObj);
This will only be useful if you don't need the format to stay in string. otherwise you'd have to convert this back to JSON using the JSON library.
Solution 5 - Javascript
var i = jsonObj.length;
while ( i --> 0 ) {
if ( jsonObj[i].Id === 3 ) {
jsonObj[ i ].Username = 'Thomas';
break;
}
}
Or, if the array is always ordered by the IDs:
jsonObj[ 2 ].Username = 'Thomas';
Solution 6 - Javascript
JSON is the JavaScript Object Notation. There is no such thing as a JSON object. JSON is just a way of representing a JavaScript object in text.
So what you're after is a way of updating a in in-memory JavaScript object. qiao's answer shows how to do that simply enough.
Solution 7 - Javascript
I took Michael Berkowski's answer a step (or two) farther and created a more flexible function allowing any lookup field and any target field. For fun I threw splat (*) capability in there incase someone might want to do a replace all. jQuery is NOT needed. checkAllRows allows the option to break from the search on found for performance or the previously mentioned replace all.
function setVal(update) {
/* Included to show an option if you care to use jQuery
var defaults = { jsonRS: null, lookupField: null, lookupKey: null,
targetField: null, targetData: null, checkAllRows: false };
//update = $.extend({}, defaults, update); */
for (var i = 0; i < update.jsonRS.length; i++) {
if (update.jsonRS[i][update.lookupField] === update.lookupKey || update.lookupKey === '*') {
update.jsonRS[i][update.targetField] = update.targetData;
if (!update.checkAllRows) { return; }
}
}
}
var jsonObj = [{'Id':'1','Username':'Ray','FatherName':'Thompson'},
{'Id':'2','Username':'Steve','FatherName':'Johnson'},
{'Id':'3','Username':'Albert','FatherName':'Einstein'}]
With your data you would use like:
var update = {
jsonRS: jsonObj,
lookupField: "Id",
lookupKey: 2,
targetField: "Username",
targetData: "Thomas",
checkAllRows: false
};
setVal(update);
And Bob's your Uncle. :) [Works great]
Solution 8 - Javascript
I think this the more efficent way than for looping.
1-First find index of item. 2-Second edit exact element. (if not exist add)
Example :
let index= jsonObj.findIndex(x => x["Id"] === 3);
if (index == -1) {
// add
jsonObj.push({ id:3, .... });
} else {
// update
jsonObj[index]["Username"]="xoxo_gossip_girl"
}
Solution 9 - Javascript
For example I am using this technique in Basket functionality.
Let us add new Item to Basket.
var productArray=[];
$(document).on('click','[cartBtn]',function(e){
e.preventDefault();
$(this).html('<i class="fa fa-check"></i>Added to cart');
console.log('Item added ');
var productJSON={"id":$(this).attr('pr_id'), "nameEn":$(this).attr('pr_name_en'), "price":$(this).attr('pr_price'), "image":$(this).attr('pr_image'), "quantity":1, "discount":0, "total":$(this).attr('pr_price')};
if(localStorage.getObj('product')!==null){
productArray=localStorage.getObj('product');
productArray.push(productJSON);
localStorage.setObj('product', productArray);
}
else{
productArray.push(productJSON);
localStorage.setObj('product', productArray);
}
itemCountInCart(productArray.length);
});
After adding some item to basket - generates json array like this
[ { "id": "95", "nameEn": "New Braslet", "price": "8776", "image": "1462012394815.jpeg", "quantity": 1, "discount": 0, "total": "8776" }, { "id": "96", "nameEn": "new braslet", "price": "76", "image": "1462012431497.jpeg", "quantity": 1, "discount": 0, "total": "76" }, { "id": "97", "nameEn": "khjk", "price": "87", "image": "1462012483421.jpeg", "quantity": 1, "discount": 0, "total": "87" }]
For Removing some item from Basket.
$(document).on('click','[itemRemoveBtn]',function(){
var arrayFromLocal=localStorage.getObj('product');
findAndRemove(arrayFromLocal,"id",$(this).attr('basketproductid'));
localStorage.setObj('product', arrayFromLocal);
loadBasketFromLocalStorageAndRender();
});
//This function will remove element by specified property. In my case this is ID.
function findAndRemove(array, property, value) {
array.forEach(function(result, index) {
if(result[property] === value) {
//Remove from array
console.log('Removed from index is '+index+' result is '+JSON.stringify(result));
array.splice(index, 1);
}
});
}
And Finally the real answer of the question "Updating a JSON object using JS". In my example updating product quantity and total price on changing the "number" element value.
$(document).on('keyup mouseup','input[type=number]',function(){
var arrayFromLocal=localStorage.getObj('product');
setQuantityAndTotalPrice(arrayFromLocal,$(this).attr('updateItemid'),$(this).val());
localStorage.setObj('product', arrayFromLocal);
loadBasketFromLocalStorageAndRender();
});
function setQuantityAndTotalPrice(array,id,quantity) {
array.forEach(function(result, index) {
if(result.id === id) {
result.quantity=quantity;
result.total=(quantity*result.price);
}
});
}
Solution 10 - Javascript
var jsonObj = [{'Id':'1','Quantity':'2','Done':'0','state':'todo',
'product_id':[315,"[LBI-W-SL-3-AG-TA004-C650-36] LAURA BONELLI-WOMEN'S-SANDAL"],
'Username':'Ray','FatherName':'Thompson'},
{'Id':'2','Quantity':'2','Done':'0','state':'todo',
'product_id':[314,"[LBI-W-SL-3-AG-TA004-C650-36] LAURA BONELLI-WOMEN'S-SANDAL"],
'Username':'Steve','FatherName':'Johnson'},
{'Id':'3','Quantity':'2','Done':'0','state':'todo',
'product_id':[316,"[LBI-W-SL-3-AG-TA004-C650-36] LAURA BONELLI-WOMEN'S-SANDAL"],
'Username':'Albert','FatherName':'Einstein'}];
for (var i = 0; i < jsonObj.length; ++i) {
if (jsonObj[i]['product_id'][0] === 314) {
this.onemorecartonsamenumber();
jsonObj[i]['Done'] = ""+this.quantity_done+"";
if(jsonObj[i]['Quantity'] === jsonObj[i]['Done']){
console.log('both are equal');
jsonObj[i]['state'] = 'packed';
}else{
console.log('not equal');
jsonObj[i]['state'] = 'todo';
}
console.log('quantiy',jsonObj[i]['Quantity']);
console.log('done',jsonObj[i]['Done']);
}
}
console.log('final',jsonObj);
}
quantity_done: any = 0;
onemorecartonsamenumber() {
this.quantity_done += 1;
console.log(this.quantity_done + 1);
}