Convert json string value to number

Question

I have a JSON string that reads:

[{
    "id": "id2",
    "index": "2",
    "str": "str2",
    "cent": "200",
    "triplet": "222"
},
{
    "id": "id3",
    "index": "3",
    "str": "str3",
    "cent": "300",
    "triplet": "333"
},
{
    "id": "id4",
    "index": "4",
    "str": "str4",
    "cent": "400",
    "triplet": "444"
},
{
    "id": "id5",
    "index": "5",
    "str": "str5",
    "cent": "500",
    "triplet": "555"
}]

The key-value pairs come dynamically from the server and I won't know beforehand what data to expect. For a charting library that I use, I need the values in JSON to be numeric rather than string viz. "index":2 instead of "index":"2" I am required to do this manipulation client-side using pure JS or jQuery.

This was my approach but it doesn't seem to work:

var temp = //some json that I receive
var jsonForChart = jQuery.extend(true, {}, temp);
$.each(temp, function(key, value) {
    $.each(value, function(k, v) {
        if(!isNaN(v)){
            jsonForChart[key][k] = Number(v);
        }
    });
});

what seems to be the problem? Are you getting any errors?

Tjaart van der Walt
– Tjaart van der Walt

2015-12-01 06:55:55 +00:00
Commented Dec 1, 2015 at 6:55 — Tjaart van der Walt
– Tjaart van der Walt, Commented Dec 1, 2015 at 6:55

Arg0n · Accepted Answer · 2017-08-11 13:00:50Z

12

Something like this (where objects is an Array of objects):

JavaScript

for(var i = 0; i < objects.length; i++){
    var obj = objects[i];
    for(var prop in obj){
        if(obj.hasOwnProperty(prop) && obj[prop] !== null && !isNaN(obj[prop])){
            obj[prop] = +obj[prop];   
        }
    }
}

console.log(JSON.stringify(objects, null, 2));

The last line will print out this:

[
  {
    "id": "id2",
    "index": 2,
    "str": "str2",
    "cent": 200,
    "triplet": 222
  },
  {
    "id": "id3",
    "index": 3,
    "str": "str3",
    "cent": 300,
    "triplet": 333
  },
  {
    "id": "id4",
    "index": 4,
    "str": "str4",
    "cent": 400,
    "triplet": 444
  },
  {
    "id": "id5",
    "index": 5,
    "str": "str5",
    "cent": 500,
    "triplet": 555
  }
]

edited Aug 11, 2017 at 13:00

answered Dec 1, 2015 at 7:05

Arg0n

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3 Comments

Mickael Bergeron Néron Over a year ago

This converts null to 0. I just spent 2 hours on a bug caused by this.

Arg0n Over a year ago

@MickaelBergeronNéron Fixed.

pramodpxi Over a year ago

Yeah this works. But Can this go a little deeper. If one of the property is object then this code should even go into that obj and convert values. Kind of recurcively.

Shanoor · Accepted Answer · 2015-12-01 07:13:39Z

You don't need to check if the value is a number:

var temp = [{
  "id": "id2",
  "index": "2",
  "str": "str2",
  "cent": "200",
  "triplet": "222"
}, {
  "id": "id3",
  "index": "3",
  "str": "str3",
  "cent": "300",
  "triplet": "333"
}, {
  "id": "id4",
  "index": "4",
  "str": "str4",
  "cent": "400",
  "triplet": "444"
}, {
  "id": "id5",
  "index": "5",
  "str": "str5",
  "cent": "500",
  "triplet": "555"
}];

var jsonForChart = jQuery.extend(true, {}, temp);
$.each(temp, function(key, value) {
  $.each(value, function(k, v) {
    // if the value can be parsed to int, it will be OR the value remains untouched
    jsonForChart[key][k] = +v || jsonForChart[key][k];
  });
});

document.write("<pre>" + JSON.stringify(jsonForChart, null, 3) + "</pre>");

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

You get one big object but it's what you expect seeing the line var jsonForChart = jQuery.extend(true, {}, temp);.

Harry Bomrah · Accepted Answer · 2015-12-01 06:58:39Z

1

Try this. I haven't tested it but should work.

var temp = //some json that I receive
var jsonForChart = jQuery.extend(true, {}, temp);
$.each(temp, function(key, value) {
    $.each(value, function(k, v) {
        if(!isNaN(parseInt(v))){
            jsonForChart[key][k] = parseInt(v);
        }else{
            jsonForChart[key][k] = v;
        }
    });
});

answered Dec 1, 2015 at 6:58

Harry Bomrah

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1 Comment

Slartibartfast Over a year ago

Doesn't make much of a difference with that else condition. Thanks for the suggestion though :)

void · Accepted Answer · 2015-12-01 06:59:44Z

1

Try this

// Iterate thorugh the array
[].forEach.call(x, function(inst, i){
    // Iterate through all the keys
    [].forEach.call(Object.keys(inst), function(y){
        // Check if string is Numerical string
        if(!isNaN(x[i][y]))
            //Convert to numerical value
            x[i][y] = +x[i][y];
    });

});

console.log(x);

Live FIddle

answered Dec 1, 2015 at 6:59

void

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1 Comment

Slartibartfast Over a year ago

Works correctly for the conversion; somehow not getting the desired result with the charts.

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