I have a JSON Array something like this:
[{ id: 1, total: 50.00 }, { id: 2, total: 70.00 }]
I would like to know how to add / change an item to a id only. Like it was in SQL.
For example, in the case I wanted to change the total of id:2 how could I do it?
If you want to change only the value of the object whose ID is 2, you will have to scroll through all the elements / objects in that array. If you cycle for you can use break; and improve performance.
Something like:
var json = [{
id: 1,
total: 50.00
}, {
id: 2,
total: 70.00
}];
alert(json[1].total); // 70
for (var i = 0; i < json.length; i++) {
var obj = json[i];
if (obj.id == 2) {
obj.total = 100;
break;
}
}
alert(json[1].total); // 100
I do not know AngularJS, but I think filter can do what you want ( just did not understand by the documentation how to use it). For pure JavaScript, you can use Array.filter :
var array = [{ id: 1, total: 50.00 }, { id: 2, total: 70.00 }];
var el = array.filter(function(el) { return el.id == 2; })[0];
el.total += 10;
document.getElementsByTagName("body")[0].innerHTML += JSON.stringify(array); find would be an even better option , but is not widely supported by all browsers.
You can add an object to the array with the method push
var lista = [{ id: 1, total: 50.00 }, { id: 2, total: 70.00 }];
lista.push({ id: 3, total: 50.00 });
But if you want to access the array quickly through id you can use an object instead of array itself.
var lista = {};
lista["1"] = { id: 1, total: 50.00 };
lista["3"] = { id: 3, total: 50.00 };
lista["5"] = { id: 5, total: 50.00 };
//Editando o valor do registro com id = 3
lista["3"].total = 300.00;
This is possible because a json object can be accessed similarly to a HashMap (Java) or Dictionary (C #), then json.Prop is the same as json["Prop"] .