NodeJS Count how many objects in array?

Question

How would I count how many objects there are inside an array?

The array looking like:

[ {id: 1}, {id: 2}, ...]

I assume I could use count() if it was PHP, but what about NodeJS/Javascript?

Edit:

asd

if (offer.items_to_receive.length > 0) { 
    console.log("items: " + offer.items_to_receive.length);
    for(var i = 0; i < offer.items_to_receive.length; i++) {
        usersInRound.push(offer.steamid_other);
    }
}

logData('Accepted trade offer from ' + offer.steamid_other + '. (tradeofferid: ' + offer.tradeofferid + ')\nWorth ' + offer.items_to_receive.length + ' tickets. ');

How come it can read the "worth X tickets", but not the other part?

if your question was caused by your own typo (something you seem to indicate in a comment), then please delete your question. — jfriend00
– jfriend00, Commented Mar 17, 2015 at 6:02
Based on your edit, offer.items_to_receive is undefined. There is some problem earlier in your code that is making that property not be what you think it is. And, you certainly can't read the .length property of undefined. This should be basic debugging of your own code. — jfriend00
– jfriend00, Commented Mar 17, 2015 at 6:07
Well how come it can read it at the end? (Check the \nWorth X tickets part) it can read the .length there? — prk
– prk, Commented Mar 17, 2015 at 6:13

Oleksandr T. · Accepted Answer · 2015-03-17 06:11:44Z

28

Use .length

var data = [{
    id: 1
}, {
    id: 2
}];

console.log(data.length);

Update, in your edit I see that

offer.items_to_receive is undefined, ensure that object offer has property items_to_receive (should be array);

edited Mar 17, 2015 at 6:11

answered Mar 17, 2015 at 5:55

Oleksandr T.

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Comments

Zuber Surya · Accepted Answer · 2015-03-17 06:08:51Z

10

list = //YOUR OBJECT DATA

count= Object.keys(list).length;

Object.keys() gives the count of keys

That should give proper count

answered Mar 17, 2015 at 6:08

Zuber Surya

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Community · Accepted Answer · 2017-05-23 11:51:17Z

1

I think your question should be How to get Array Size in Javascript?

Answer: Use the length method.

Examples:

[1,2,3].length
// => 3

var a = { num: 1, obj: {}, arr: [{}, 3, "asd", {q: 3}, 1] }
a.arr.length
// => 5

edited May 23, 2017 at 11:51

CommunityBot

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answered Mar 17, 2015 at 5:58

Sheharyar

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Comments

Prakash · Accepted Answer · 2024-08-06 09:45:36Z

0

a.arr.length

.length is not working while used in express it says deprecated

Error: express deprecated res.send(status): Use res.sendStatus(status) instead

answered Aug 6, 2024 at 9:45

Prakash

1

2 Comments

ruud Over a year ago

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Community Over a year ago

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center.

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