Query through Json object

Question

This is my JSON:

[{"Id":1,"Order":1,"IsDone":true,"Text":"abc","Date":"6/14/2014"},
 {"Id":2,"Order":2,"IsDone":false,"Text":"cde","Date":"6/15/2014"},
 {"Id":3,"Order":3,"IsDone":false,"Text":"fgh","Date":"6/16/2014"}]

What would be the most efficient way to get the count of IsDone == true?

You code doesn't look like JSON object, rather it's an array of objects. Also, this is very basic task in JavaScript, what have you tried? — Teemu, Jun 19 '14 at 06:47
The most efficient way is to use a for loop. here's the explanation => http://stackoverflow.com/questions/8550183/sum-of-values-in-an-array-using-jquery — HandsomeG, Jun 19 '14 at 06:49
I did do the loop approach. But just wondering if there are another way to tackle this. By the way thanks. — dausdashsan, Jun 19 '14 at 06:52
"most efficient" in what way? I doubt any of the posted answers will be faster than a regular `for` loop. Unless the data is sorted you will need to loop through all elements in the array. — Andy Gaskell, Jun 19 '14 at 06:59
1. if the data is sorted, the counting process will be faster. 2. or you can return one more object (which is already count the data from the server), example: {totalDone:5} — Mr.Cocococo, Jun 19 '14 at 07:10

score 3 · Accepted Answer · answered Jun 19 '14 at 06:52

You can use plain javascript iteration:

var a=[{"Id":1,"Order":1,"IsDone":true,"Text":"abc","Date":"6/14/2014"},{"Id":2,"Order":2,"IsDone":false,"Text":"cde","Date":"6/15/2014"},{"Id":3,"Order":3,"IsDone":false,"Text":"fgh","Date":"6/16/2014"}]

var ct=0;
a.forEach(function(entry) {
    if(entry.IsDone)ct++;
});
alert(ct);

Mourice · Answer 2 · 2014-06-19T07:09:59.400

Use grep fron jquery

var selectedArray = [{"Id":1,"Order":1,"IsDone":true,"Text":"abc","Date":"6/14/2014"},
{"Id":2,"Order":2,"IsDone":false,"Text":"cde","Date":"6/15/2014"},
{"Id":3,"Order":3,"IsDone":false,"Text":"fgh","Date":"6/16/2014"}]



selectedArray = jQuery.grep(selectedArray, function (el) { return el.IsDone == true;   });

 alert(selectedArray.length);

where seletedArray is your actual array

http://jsfiddle.net/QxV6K/

abhinsit · Answer 3 · 2014-06-19T06:56:34.147

0

In case you're trying to access an item from the example structure by id or name, without knowing it's position in the array, the easiest way to do it would be to use underscore.js library:

    var data =   [{"Id":1,"Order":1,"IsDone":true,"Text":"abc","Date":"6/14/2014"},{"Id":2,"Order":2,"IsDone":false,"Text":"cde","Date":"6/15/2014"},{"Id":3,"Order":3,"IsDone":false,"Text":"fgh","Date":"6/16/2014"}];

    var allDesiredElements = _.filter(data, function(item) {
      return item.IsDone === true;
    });

//for length use
console.log(allDesiredElements.length);

edited Jun 19 '14 at 06:56

answered Jun 19 '14 at 06:50

abhinsit

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`_.find` just finds the first one, not all of them. – Barmar Jun 19 '14 at 06:52
I think you actually want `_.filter`. – Barmar Jun 19 '14 at 06:53

score 0 · Answer 4 · answered Jun 19 '14 at 06:53

var data = [{"Id":1,"Order":1,"IsDone":true,"Text":"abc","Date":"6/14/2014"},{"Id":2,"Order":2,"IsDone":false,"Text":"cde","Date":"6/15/2014"},{"Id":3,"Order":3,"IsDone":false,"Text":"fgh","Date":"6/16/2014"}];

var count = data.filter(function (el) {
  return (el.IsDone === true);
});

alert(count.length);

DEMO

score 0 · Answer 5 · answered Jun 19 '14 at 06:56

try this one

 var obj = [{"Id":1,"Order":1,"IsDone":true,"Text":"abc","Date":"6/14/2014"},
    {"Id":2,"Order":2,"IsDone":false,"Text":"cde","Date":"6/15/2014"},
    {"Id":3,"Order":3,"IsDone":false,"Text":"fgh","Date":"6/16/2014"}]

    var count = 0;
    for(i=0;i<obj.length;i--){
      count += (obj[i].IsDone) ? 1 : 0;
    }

Query through Json object

5 Answers5