Get JSON array length based on its attribute value

Question

How to get JSON array length efficiently in jquery based on its attribute value.

for example array is:

var arr = [{
    "name":"amit",
    "online":true
},{
    "name":"rohit",
    "online":false
},{
    "name":"kk",
    "online":true
},{
    "name":"mohit",
    "online":true
},];

I want to get online users length i.e where online = true.

You would need to loop over the object and count the number of objects with that property value. Better yet, assuming this JSON is coming from a server, change the endpoint to only return the users where `online = true` — Rory McCrossan, Nov 03 '15 at 09:31
Possible duplicate of [Length of a JavaScript object (that is, associative array)](http://stackoverflow.com/questions/5223/length-of-a-javascript-object-that-is-associative-array) — Nam Pham, Nov 03 '15 at 10:22

score 1 · Accepted Answer · answered Nov 03 '15 at 09:30

1

You can use .filter

Try like this

console.log(arr.filter(function(x){ return x.online;}).length)

JSFIDDLE

answered Nov 03 '15 at 09:30

Anik Islam Abhi

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score 1 · Answer 2 · answered Nov 03 '15 at 09:31

try this using jQuery grep

  var arr = [
        {"name":"amit",
        "online":true},
        {"name":"rohit",
        "online":false},
        {"name":"kk",
        "online":true},
        {"name":"mohit",
        "online":true},
    ];

 var data =  jQuery.grep(arr, function(obj) {
     return obj.online == true;
 });

    console.log(data.length)

score 0 · Answer 3 · answered Nov 03 '15 at 09:31

var arr = [{
    "name":"amit",
    "online":true
},{
    "name":"rohit",
    "online":false
},{
    "name":"kk",
    "online":true
},{
    "name":"mohit",
    "online":true
}];
var count = 0;
for(var i = 0; i < arr.length; i++){
    if(arr[i].online == true){
        count++
    }
}

console.log(count);

Try this way you will get 3

Get JSON array length based on its attribute value

3 Answers3