javascript - How to check if JSON array is equal to - Stack Overflow

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I am creating pie charts with JSON and Flot. The JS function to create the pie chart receives a JSON array from Django in this format:

[1, 3, 2, 5, 4]

If there is no data, the JSON array is:

[0, 0, 0, 0, 0]

I'm trying to adjust the function so that if there is no data, then the pie will not be plotted and some text will appear instead (e.g. "Nothing to show yet"). So far I have tried:

function loadWeekChart(theData) {
    var blankData = [0, 0, 0, 0, 0];
    if ($.data(theData) == $.data(blankData)){
    $('#week-pie-chart').empty().append('Nothing to show yet');
    } else {
        $.plot($("#week-pie-chart"), theData ,
            {
                series: {
                    pie: { 
                        show: true
                    }
                }
            });
     }
}

The JS doesn't fail, but it neither prints a pie chart (there is no data) nor does it give me the text replacement.

Please can someone show me where I'm going wrong!

I am creating pie charts with JSON and Flot. The JS function to create the pie chart receives a JSON array from Django in this format:

[1, 3, 2, 5, 4]

If there is no data, the JSON array is:

[0, 0, 0, 0, 0]

I'm trying to adjust the function so that if there is no data, then the pie will not be plotted and some text will appear instead (e.g. "Nothing to show yet"). So far I have tried:

function loadWeekChart(theData) {
    var blankData = [0, 0, 0, 0, 0];
    if ($.data(theData) == $.data(blankData)){
    $('#week-pie-chart').empty().append('Nothing to show yet');
    } else {
        $.plot($("#week-pie-chart"), theData ,
            {
                series: {
                    pie: { 
                        show: true
                    }
                }
            });
     }
}

The JS doesn't fail, but it neither prints a pie chart (there is no data) nor does it give me the text replacement.

Please can someone show me where I'm going wrong!

• javascript
• arrays
• json
• equals
• flot

Share Improve this question Follow edited Jul 24, 2012 at 9:29 Sirko 74.1k1919 gold badges154154 silver badges189189 bronze badges asked Jul 24, 2012 at 9:24 Erve1879Erve1879 84511 gold badge1414 silver badges2626 bronze badges 1

• 1 Arrays must be pared element by element to check "equality'. – Zéychin Commented Jul 24, 2012 at 9:43

Add a ment  | 

5 Answers 5

Sorted by: Reset to default 2

Personaly i would do the following heres the psuedo code...

set boolean to true
for each element in the JSON
    pare it with blank data element 
    if they are not equal boolean false
    else continue
return boolean

Then you will know if there same as that function returns true if they are false if they aren't.

Please let me know if you need help coding this. Shouldn't that hard

This may also help: Similar Question

function checkJsons(otherJson,newJson)
{
    var sameJson = true;
     for (var key in otherJson) {
        if(otherJson[key] != newJson[key]) {sameJson=false;} return sameJson;
     }
}

That should help, not test though

A nicer way to do this but harder to read is

function checkJsons(otherJson,newJson)
{
  for (var key in otherJson) {if(otherJson[key] != newJson[key]) {return false;}}
  return true;
}

function pieChartData(theData)
{
  var blankData = [0, 0, 0, 0, 0];
 if(checkJsons(blankData,theData)){$('#week-pie-chart').empty().append('Nothing to show yet');} else { // do your code here // }
} 

I should think something like this should work:

var replace = true;
for(var i = 0; i < theData.length; i++)
{
    if(theData.[i] != 0)
    {
        replace = false;
        break;
    }
}

if(replace)
{
     $('#week-pie-chart').empty().append('Nothing to show yet');
}

else
{
    $.plot($("#week-pie-chart"), theData ,
        {
            series: {
                pie: { 
                    show: true
                }
            }
        });
}

how about use JSON.stringify?

l1 = [0, 0, 0, 0];
l2 = [0, 0, 0, 1];
var bEqual = JSON.stringify(l1) == JSON.stringify(l2);
console.log(bEqual);

You don't need to pare with 0-filled array. Just check the input array is 0-filled. I think reduce() is the best for this:

if(arr.reduce(function(a, b){ return a + b; }) == 0) {
    //Nothing to show
} else {
    ...

...but older browsers don't support reduce(), so I suggest using $.grep() instead (because you're already using jQuery).

if($.grep(theData, function (a) { return a != 0; }).length == 0) {
    //Nothing to show
} else {
    ...

LmC's answer is good for paring to JSON objects. I adapted it to pare two JSON arrays which can even have nested JSON arrays. Here is the code:

var areJSONArraysEqual = function(jsonArray1,
                                    jsonArray2) {

                                if(jsonArray1.length===0||jsonArray2.length===0){
                                    if(jsonArray1.length===0 && jsonArray2.length===0){
                                        return true;
                                    }else{
                                        return false;
                                    }
                                }

                                for(var i=0;i<jsonArray1.length;i++){
                                    for ( var key in jsonArray1[i]) {
                                        if(jsonArray1[i][key].length>1){
                                            return areJSONArraysEqual(jsonArray1[i][key],jsonArray2[i][key])
                                        }
                                        if (jsonArray1[i][key] != jsonArray2[i][key]) {
                                            return false;
                                        }
                                    }
                                }
                                return true;
                            };

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