Remove JSON element

I want to remove JSON element or one whole row from JSON.

I have following JSON string:

{
   "result":[
       {
           "FirstName": "Test1",
           "LastName":  "User",
       },
       {
           "FirstName": "user",
           "LastName":  "user",
       },
       {
           "FirstName": "Ropbert",
           "LastName":  "Jones",
       },
       {
           "FirstName": "hitesh",
           "LastName":  "prajapti",
       }
   ]
}

var json = { ... };
var key = "foo";
delete json[key]; // Removes json.foo from the dictionary.

You can use splice to remove elements from an array.

Do NOT have trailing commas in your OBJECT (JSON is a string notation)

UPDATE: you need to use array.splice and not delete if you want to remove items from the array in the object. Alternatively filter the array for undefined after removing

var data = {
  "result": [{
    "FirstName": "Test1",
    "LastName": "User"
  }, {
    "FirstName": "user",
    "LastName": "user"
  }]
}
console.log(data.result);
console.log("------------ deleting -------------");
delete data.result[1];
console.log(data.result); // note the "undefined" in the array.


data = {
  "result": [{
    "FirstName": "Test1",
    "LastName": "User"
  }, {
    "FirstName": "user",
    "LastName": "user"
  }]
}

console.log(data.result);
console.log("------------ slicing -------------");
var deletedItem = data.result.splice(1,1);
console.log(data.result); // here no problem with undefined.

You can try to delete the JSON as follows:

var bleh = {first: '1', second: '2', third:'3'}

alert(bleh.first);

delete bleh.first;

alert(bleh.first);

Alternatively, you can also pass in the index to delete an attribute:

delete bleh[1];

However, to understand some of the repercussions of using deletes, have a look here

For those of you who came here looking for how to remove an object from an array based on object value:

let users = [{name: "Ben"},{name: "Tim"},{name: "Harry"}];

let usersWithoutTim = users.filter(user => user.name !== "Tim");

// The old fashioned way:

for (let [i, user] of users.entries()) {
  if (user.name === "Tim") {
    users.splice(i, 1); // Tim is now removed from "users"
  }
}

Note: These functions will remove all users named Tim from the array.

I recommend splice method to remove an object from JSON objects array.

jQuery(json).each(function (index){
        if(json[index].FirstName == "Test1"){
            json.splice(index,1); // This will remove the object that first name equals to Test1
            return false; // This will stop the execution of jQuery each loop.
        }
});

I use this because when I use delete method, I get null object after I do JSON.stringify(json)

All the answers are great, and it will do what you ask it too, but I believe the best way to delete this, and the best way for the garbage collector (if you are running node.js) is like this:

var json = { <your_imported_json_here> };
var key = "somekey";
json[key] = null;
delete json[key];

This way the garbage collector for node.js will know that json['somekey'] is no longer required, and will delete it.

1. Fix the errors in the JSON: http://jsonlint.com/
2. Parse the JSON (since you have tagged the question with JavaScript, use json2.js)
3. Delete the property from the object you created
4. Stringify the object back to JSON.

As described by @mplungjan, I though it was right. Then right away I click the up rate button. But by following it, I finally got an error.

<script>
var data = {"result":[
  {"FirstName":"Test1","LastName":"User","Email":"[email protected]","City":"ahmedabad","State":"sk","Country":"canada","Status":"False","iUserID":"23"},
  {"FirstName":"user","LastName":"user","Email":"[email protected]","City":"ahmedabad","State":"Gujarat","Country":"India","Status":"True","iUserID":"41"},
  {"FirstName":"Ropbert","LastName":"Jones","Email":"[email protected]","City":"NewYork","State":"gfg","Country":"fgdfgdfg","Status":"True","iUserID":"48"},
  {"FirstName":"hitesh","LastName":"prajapti","Email":"[email protected]","City":"","State":"","Country":"","Status":"True","iUserID":"78"}
  ]
}
alert(data.result)
delete data.result[3]
alert(data.result)
</script>

Delete is just remove the data, but the 'place' is still there as undefined.

I did this and it works like a charm :

data.result.splice(2,1);  

meaning : delete 1 item at position 3 ( because array is counted form 0, then item at no 3 is counted as no 2 )

Try this following

var myJSONObject ={"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};
console.log(myJSONObject);
console.log(myJSONObject.ircEvent);
delete myJSONObject.ircEvent 
delete myJSONObject.regex 
console.log(myJSONObject);

if we want to remove one attribute say "firstName" from the array we can use map function along with delete as mentioned above

   var result= [
       {
           "FirstName": "Test1",
           "LastName":  "User",
       },
       {
           "FirstName": "user",
           "LastName":  "user",
       },
       {
           "FirstName": "Ropbert",
           "LastName":  "Jones",
       },
       {
           "FirstName": "hitesh",
           "LastName":  "prajapti",
       }
   ]

result.map( el=>{
    delete el["FirstName"]
})
console.log("OUT",result)

try this

json = $.grep(newcurrPayment.paymentTypeInsert, function (el, idx) { return el.FirstName == "Test1" }, true)

Could you possibly use filter? Say you wanted to remove all instances of Ropbert

let result = [
   {
       "FirstName": "Test1",
       "LastName":  "User",
   },
   {
       "FirstName": "user",
       "LastName":  "user",
   },
   {
       "FirstName": "Ropbert",
       "LastName":  "Jones",
   },
   {
       "FirstName": "hitesh",
       "LastName":  "prajapti",
   }
   ]

result = result.filter(val => val.FirstName !== "Ropbert")

(result now contains)

[
   {
       "FirstName": "Test1",
       "LastName":  "User",
   },
   {
       "FirstName": "user",
       "LastName":  "user",
   },
   {
       "FirstName": "hitesh",
       "LastName":  "prajapti",
   }
   ] 

You can add further values to narrow down the items you remove, for example if you want to remove on first and last name then you could do this:

result = result.filter(val => !(val.FirstName === "Ropbert" && val.LastName === "Jones"))

Although as noted, if you have 4 'Ropbert Jones' in your array, all 4 instances would be removed.