remove key(s) from a json array under javascript

Question

Need to remove key(s) from a json array under javascript (jquery). Looks like my code is wong although it was working in my Chrome console. Your help is the most welcome. Jacques

function test() {
 var json = {
 "ID": "2196",
 "VERSION": "1-2022",
 "FILE": "2196.docx"
 };
 json = JSON.stringify(json)
 console.log("json " + json);
 delete json['FILE'];
 console.log("json " + json);
 return;
}
test();

• Barmar: You can't delete from JSON, you have to delete from the original object before stringifying, or parse the JSON, delete the key, then stringify again.
• Mark Baijens: Well you could delete it from a string as well (with some different code), but I'd say deleting it from the object is way better and easier.

Answer 1

JSON.stringify has an often overlooked parameter called the replacer. It can accept an array of key names to include in the json output:

 JSON.stringify(data, ["ID","VERSION"], " "); // FILE is excluded 

Snippet

Run the snippet to see the output with and without using the replacer.

let data = {
 "ID": "2196",
 "VERSION": "1-2022",
 "FILE": "2196.docx"
};
console.log("Without replacer: ",
 JSON.stringify(data, null, " ")
);
console.log("Using replacer: ",
 JSON.stringify(data, ["ID","VERSION"], " ")
);

Answer 2

You should not stringify the object before removing the key.

function test() {
 var json = {
 "ID": "2196",
 "VERSION": "1-2022",
 "FILE": "2196.docx"
 };
 // stringify to show in console as string
 json = JSON.stringify(json)
 console.log("json " + json);
 // convert back to object so you can remove the key
 json = JSON.parse(json);
 delete json['FILE'];
 
 // stringify to show new object in console as string
 json = JSON.stringify(json);
 console.log("json " + json);
 return;
}
test();

• Jacques tambard: Thanks for the explanation regarding the use of stringify. Afterwards it makes sense. Thanks to you Folks.