Javascript filter was unfair

Question

I'm trying to get existCount from an array, which has id in selected array.

But something went wrong, I had an item with id = 5493 but existCount.length 0

My JS code:

var existCount = $scope.selectedScript.filter(function (item) {
    return item.id === script.script_id;
});
console.log('existCount.length ', existCount.length);
console.log('$scope.selectedScript ', $scope.selectedScript);
console.log('script.script_id ', script.script_id);

Chrome Console view:

https://i.stack.imgur.com/4UVWw.png

// Sorry I forgot the first output line, but this line's at the top of $scope.selectedScript and it was existCount.length = 0

Where my fault?

How can I fix it?

Thanks!

Please don't post [images of code](https://idownvotedbecau.se/imageofcode). [Edit] your question to format your code as blocks using the `{ }` icon or Ctrl+K. — Patrick Roberts, Nov 20 '18 at 00:02

nhaht · Accepted Answer · 2018-11-20T00:18:08.267

1

Change return item.id === script.script_id; to return item.id == script.script_id;

In your case: item.id was a number, script.script_id was a string. You can see it in chrome debug by color, black for string, blue for number.

=== is the hard way to compare in JS.

You can see at https://stackoverflow.com/a/359509/8572205

So === return false and no item added into existCount

edited Nov 20 '18 at 00:18

answered Nov 20 '18 at 00:10

nhaht

1,005
12
21

Did you try it? – nhaht Nov 20 '18 at 00:14

score 0 · Answer 2 · answered Nov 20 '18 at 00:09

0

if you use triple-equals ===, make sure both the values in comparison are of same type. I suspect script.script_id is a string.

Try changing === to ==

answered Nov 20 '18 at 00:09

Dinesh Pandiyan

5,814
2
30
49

Javascript filter was unfair

2 Answers2