Concatenate Object values

I have a JavaScript Object and I’m sure the value of any key is an array (even empty in some case): {key1:[“a”,”b”,”c”],key2:[“d”,”e”,”f”],key3:…} Aside from using Underscore, is there any way to …

Sum similar keys in an array of objects

I have an array of objects like the following: I need to add up all the values for objects with the same name. (Probably also other mathematical operations like calculate average.) For the example above the result would be: Answer First iterate through the array and push the ‘name’ into another object’s property. If the property exists add the ‘value’ to the value of the property otherwise initialize the property to the ‘value’. Once you build this object, iterate through the properties and push them to another array. Here is some code: Hope this helps.

How to remove last key:value pair in JavaScript

I am very new to JavaScript and I am trying to figure out how to set a function to remove the last key:value pair to the right, much like array.pop for an array. This is an assignment I am working on. …

javascript find and remove object in array based on key value

I have been trying several approaches on how to find an object in an array, where ID = var, and if found, remove the object from the array and return the new array of objects. Data: I’m able to search the array using jQuery $grep; But how can I delete the entire object when id == 88, and return data like this: Data: Answer I can grep the array for the id, but how can I delete the entire object where id == 88 Simply filter by the opposite predicate:

Sort array of objects by single key with date value

I have an array of objects with several key value pairs, and I need to sort them based on ‘updated_at’: [ { “updated_at” : “2012-01-01T06:25:24Z”, “foo” : “bar” }, { …

Generic deep diff between two objects

I have two objects: oldObj and newObj. The data in oldObj was used to populate a form and newObj is the result of the user changing data in this form and submitting it. Both objects are deep, ie. they …

Set of objects in javascript

I’d like to have a set of objects in Javascript. That is, a data structure that contains only unique objects. Normally using properties is recommended, e.g. myset[“key”] = true. However, I need the …

Javascript event firing before action occurs

I am trying to write a script so that when I play an embedded sound object, a picture that I also have embedded will change. function changePic() { document.getElementById(“sound”).onclick = …

How to determine whether an object has a given property in JavaScript

How can I determine whether an object x has a defined property y, regardless of the value of x.y? I’m currently using if (typeof(x.y) !== ‘undefined’) but that seems a bit clunky. Is there a better …

Sorting a JavaScript object by property name

I’ve been looking for a while and want a way to sort a Javascript object like this: { method: ‘artist.getInfo’, artist: ‘Green Day’, format: ‘json’, api_key: ‘…