Using jQuery grep on an object

Question

I have an object which looks like that:

const myObject = {
  3723723: null
 ,3434355: true
 ,9202002: null
}

Using jQuery grep method I need to get the count of the array where the value is not null.

const result = $.grep(myArray, function (k, v) { return v != null; });
const count = result.length;

Michał Perłakowski · Accepted Answer · 2016-08-17 18:22:38Z

4

The variable you're talking about is actually not an array, but an object.

You don't need jQuery to find the number of values which are not null. Call the Object.values() function to get the values of that object as an array, then use the filter() method to filter out values which are null and then check the length property.

const myObject = {
  3723723: null
 ,3434355: true
 ,9202002: null
}

console.log(Object.values(myObject).filter(x => x !== null).length)

Alternative solution using Object.keys():

const myObject = {
  3723723: null
 ,3434355: true
 ,9202002: null
}

console.log(Object.keys(myObject)
  .map(x => myObject[x])
  .filter(x => x !== null).length)

edited Aug 17, 2016 at 18:22

answered Aug 17, 2016 at 18:04

Michał Perłakowski

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8 Comments

Blake Rivell Over a year ago

Thank you for clearing that up. This works perfectly. I was looking at it as an array when really it was an object. Can you look at this post and explain how selected is getting populated and turning into an object? docs.telerik.com/devtools/aspnet-ajax/controls/grid/how-to/…. I am assuming when selected[mailID] = true happens it adds a property called id to the object with a value of true?

Michał Perłakowski Over a year ago

@BlakeRivell It was always an object. The curly braces ({}) denote an object, and the square braces ([]) denote an array. Yes, selected[mailID] = true assigns true to selected property called mailID.

Blake Rivell Over a year ago

Thanks for clearing that up. I keep getting an error saying Object.values is not defined.

Michał Perłakowski Over a year ago

@BlakeRivell Well, Object.values() is an experimental function of JavaScript and it works only in the latest Chrome and Firefox. If you want it to work in all browsers, you'll probably need Babel to compile your code.

Blake Rivell Over a year ago

I am using the latest version of chrome and your snippet errors too. It is so strange because Object.keys works fine but I am unable to filter on value if I use Object.keys.

|

Michał Perłakowski · Accepted Answer · 2016-08-17 18:19:30Z

2

In JavaScript you can use objects to get data structure you want.

var data = {
  3723723: null,
  3434355: true,
  9202002: null
}

And to count properties where the value isn't null you can use Object.keys() to get array of object keys and then reduce() to get count.

var data = {
  3723723: null,
  3434355: true,
  9202002: null
}

var result = Object.keys(data).reduce(function(r, e) {
  if(data[e] != null) r += 1;
  return r;
}, 0);

console.log(result)

edited Aug 17, 2016 at 18:19

Michał Perłakowski

93.4k30 gold badges165 silver badges189 bronze badges

answered Aug 17, 2016 at 18:02

Nenad Vracar

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