How to transform all JSON keys to lowercase in javascript?

Question

Actually, my requirement is to convert whole JSON(only keys) into lowercase. I tried it's converting only first key of that JSON and it's not converting whole all key. Please have a look the fiddle link or please provide any other ways to do this.

Thanks...

var obj = {
  "Collections": {
    "conTainer": {
      "rowSet": [{
        "containerIsArchived": "Null",
        "containerOrderNo": "26",
        "versionNum": "0",
        "containerGlobalUniqueId": "Null",
        "containerIsTenantBased": "true",
        "containerCreatedBy": "user",
        "containerIsDeleted": "false",
        "containerTenantId": "292FEC76-5F1C-486F-85A5-09D88096F098",
        "containerLayoutId": "4e13dfcd-cd3b-4a29-81bd-0f73cf9577cf",
        "containerApplicationId": "0000000-0000-0000-0000-000000000000",
        "containerIsActive": "Null",
        "containerHeaderText": "apitest19feb16",
        "containerId": "3745b273-c48d-4c94-b576-3d7aac2f7ac6",
        "containerCreatedUTCDate": "2016-02-19 17:57:51.0"
      }]
    }
  }
};

convertKeysToCamelCase(obj);

function convertKeysToCamelCase(obj) {
  if (!obj || typeof obj !== "object") return null;

  if (obj instanceof Array) {
    return $.map(obj, function(value) {
      return convertKeysToCamelCase(value);
    });
  }

  var newObj = {};
  $.each(obj, function(key, value) {
    key = key.charAt(0).toLowerCase() + key.slice(1);
    newObj[key] = value;
  });
  console.log(newObj);
  return newObj;
};

Here the Fiddle link: fiddle

please add the relevant code to your question, not just a fiddle link — Luca, Mar 29 '16 at 09:39
Did you get an error message telling you to put the code in the question instead of just linking to JS Fiddle? You need to put the code in the question and not just say that a link to JS Fiddle is code. — Quentin, Mar 29 '16 at 09:39
@DipaliVasani ..In my case JSON differ from that. it has object inside array. — bagya, Mar 29 '16 at 09:51

Nofi · Accepted Answer · 2016-03-30T11:26:58.747

8

Try the below code

function ConvertKeysToLowerCase(obj) {
    var output = {};
    for (i in obj) {
        if (Object.prototype.toString.apply(obj[i]) === '[object Object]') {
           output[i.toLowerCase()] = ConvertKeysToLowerCase(obj[i]);
        }else if(Object.prototype.toString.apply(obj[i]) === '[object Array]'){
            output[i.toLowerCase()]=[];
             output[i.toLowerCase()].push(ConvertKeysToLowerCase(obj[i][0]));
        } else {
            output[i.toLowerCase()] = obj[i];
        }
    }
    return output;
};

JsFiddle

edited Mar 30 '16 at 11:26

answered Mar 29 '16 at 09:51

Nofi

2,107
1
15
23

Would only change toLowerCase instead of toUpperCase, to respond to the question, and change the name of the function ConvertKeysToLowerCase to be truthful – Mario Chueca Mar 29 '16 at 09:57
Yeah. I already changed. Thank you very much – bagya Mar 29 '16 at 10:45
2

@MarioChueca - Actually one glitch is there in our coding. It's converting everything to object. I need an actual JSON format as it is with key lower case. here the problem is rowset is an array that is changing to object instead of array of object. – bagya Mar 30 '16 at 11:01
A warning from a time traveler from 2022: this is only handling the first item in arrays so don't just copy paste this function blindly. – Jason Sep 12 '22 at 20:45

score 3 · Answer 2 · edited May 23 '17 at 12:32

you can have a reference from @Christophe's Answer

If you can't understand here is the code for you : link

js:

var obj = {
  "Collections": {
    "conTainer": {
      "rowSet": [{
        "containerIsArchived": "Null",
        "containerOrderNo": "26",
        "versionNum": "0",
        "containerGlobalUniqueId": "Null",
        "containerIsTenantBased": "true",
        "containerCreatedBy": "user",
        "containerIsDeleted": "false",
        "containerTenantId": "292FEC76-5F1C-486F-85A5-09D88096F098",
        "containerLayoutId": "4e13dfcd-cd3b-4a29-81bd-0f73cf9577cf",
        "containerApplicationId": "0000000-0000-0000-0000-000000000000",
        "containerIsActive": "Null",
        "containerHeaderText": "apitest19feb16",
        "containerId": "3745b273-c48d-4c94-b576-3d7aac2f7ac6",
        "containerCreatedUTCDate": "2016-02-19 17:57:51.0"
      }]
    }
  }
};
var json = JSON.stringify(obj);
var newJson = json.replace(/"([\w]+)":/g, function($0, $1) {
  return ('"' + $1.toLowerCase() + '":');
});
var newObj = JSON.parse(newJson);
console.debug(newObj);

score 2 · Answer 3 · answered Mar 29 '16 at 10:13

Here is an idea, I hope it's useful.

var obj = {
    "containerIsArchived": "Null",
    "containerOrderNo": "26",
    "versionNum": "0",
    "containerGlobalUniqueId": "Null",
    "containerIsTenantBased": "true",
    "containerCreatedBy": "user",
    "containerIsDeleted": "false",
    "containerTenantId": "292FEC76-5F1C-486F-85A5-09D88096F098",
    "containerLayoutId": "4e13dfcd-cd3b-4a29-81bd-0f73cf9577cf",
    "containerApplicationId": "0000000-0000-0000-0000-000000000000",
    "containerIsActive": "Null",
    "containerHeaderText": "apitest19feb16",
    "containerId": "3745b273-c48d-4c94-b576-3d7aac2f7ac6",
    "containerCreatedUTCDate": "2016-02-19 17:57:51.0"
  };  

for(var i in obj){
    obj[i.toLowerCase()] = obj[i]; 
    delete obj[i];
}

console.log(obj);

The last statement prints the object with all keys in lowercase. The idea is to create a new key -- the lowercase version of any given key --, then get rid of the old one.

score 1 · Answer 4 · answered Mar 29 '16 at 09:58

Modify the below answer a bit to make it easier to read

function convertKeysToCamelCase(obj) {
    var output = {}
    for (var i in obj) {
        var current = obj[i]
        if (isObject(current) || isArray(current)) {
            output[i.toLowerCase()] = convertKeysToCamelCase(current);
        } else {
            output[i.toLowerCase()] = current;
        }
    }
    return output;
};

function isObject(obj) {
    return typeof obj === 'object'
}

function isArray(arr) {
    return Array.isArray(arr)
}

console.log(JSON.stringify(convertKeysToCamelCase(input)));

score 0 · Answer 5 · answered Mar 29 '16 at 09:55

You need to recurse into the object so that the keys at the lower level are covered. To do this, it would be better to create a copy of the object first and then modify that, like so

// create copy of object
var newObj = JSON.parse(JSON.stringify(obj));
convertKeysToCamelCase(newObj);

function convertKeysToCamelCase(obj) {
    if (!obj || typeof obj !== "object") return null;

    if (obj instanceof Array) {
        return $.map(obj, function(value) {
            return convertKeysToCamelCase(value);
        });
    }

    // manipulates the object being passed in
    $.each(obj, function(key, value) {
        // delete existing key
        delete obj[key];
        key = key.charAt(0).toLowerCase() + key.slice(1);
        obj[key] = value;
        convertKeysToCamelCase(value);
    });

    return obj;
};

Fiddle - http://jsfiddle.net/sbbnmz0b/

How to transform all JSON keys to lowercase in javascript?

5 Answers5

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