Format json output programatically in javascript/typescript

Question

How can I format the json output file to format the content like in the example?

[
  {"keyA1": "value1", "keyA2": "value2", "KeyAN": "valueN"},
  {"keyB1": "value1", "keyB2": "value2", "KeyBN": "valueN"},
  {"keyC1": "value1", "keyC2": "value2", "KeyCN": "valueN"},
]

There are a ton of answers like this other answer but this is not how I want it.

EDIT: maybe the question is not clear to everyone. I want the json file to be formated like this, not the javascript.

EDIT 2: this is how I am doing it now:

    const newAdmin = { 
        id: Math.floor(dateNow.getTime() / 1000), 
        firstName: firstName, 
        lastName: lastName, 
        birthDate: new Date(birthDate).toLocaleDateString(),
        registrationDay: dateNow.toLocaleDateString()
    };
    members.push(newAdmin);

    await Deno.writeFile(membersFilePath!, encoder.encode(JSON.stringify(members, null, 1)));

If you don't mind me asking, what is the added benefit of formatting your JSON this way? Do you need it to be human readable? If so, have you considered reading the JSON and presenting it in a readable fashion with the browser? — Emiel Zuurbier, Dec 15 '22 at 09:06

score 2 · Answer 1 · answered Dec 10 '22 at 22:34

2

You can try mapping through each item individually and stringifying, then joining together by a linebreak:

var arr = [{"keyA1": "value1", "keyA2": "value2", "KeyAN": "valueN"},{"keyB1": "value1", "keyB2": "value2", "KeyBN": "valueN"},{"keyC1": "value1", "keyC2": "value2", "KeyCN": "valueN"},]

const result = "[\n" + arr.map(e => '  ' + JSON.stringify(e)).join(',\n') + "\n]";

console.log(result)

answered Dec 10 '22 at 22:34

Sourabh Burse

359
2
7

I don't know what I am doing wrong but this is the output in the json file: "[\n {\"id\":1670713260,\"user\":\"new user\",\"city\":\"berlin\",\"registrationDay\":\"12/11/2022\"}\n]" – Tinaira Dec 10 '22 at 23:04
1

This might help you: https://stackoverflow.com/questions/34648904/how-can-i-remove-escape-sequences-from-json-stringify-so-that-its-human-readabl – Sourabh Burse Dec 12 '22 at 20:26

Feras Wilson · Answer 2 · 2022-12-10T23:05:59.013

-1

How about a manual way of doing it. Check the code below:

const data = [{"keyA1": "value1", "keyA2": "value2", "KeyAN": "valueN"},{"keyB1": "value1", "keyB2": "value2", "KeyBN": "valueN"},{"keyC1": "value1", "keyC2": "value2", "KeyCN": "valueN"},];

        let json = "[";

        for (const item of data) {
            json += "\n  {";

            for (const key in item) {
                json += `"${key}": "${item[key]}",`;
            }

            json += "},";
        }

        json += "\n]";

        console.log(json);

edited Dec 10 '22 at 23:05

answered Dec 10 '22 at 22:40

Feras Wilson

380
1
3
13

This is not OP was asking for, Please re-read the question. – Sourabh Burse Dec 10 '22 at 22:41
Edited the question to make the answer output exactly as the OP requested. – Feras Wilson Dec 10 '22 at 22:46
@Tinaria, check out this answer. – Feras Wilson Dec 10 '22 at 23:09
the json file is not coming out in the right format. I have no idea what I am doing wrong. I read the json file, push a new object into it. and that new array I am trying to write. but the format is not as desired – Tinaira Dec 10 '22 at 23:37
How are you outputting to the file, share your code. – Feras Wilson Dec 11 '22 at 21:52
I will edit my question and write it there – Tinaira Dec 17 '22 at 20:10

Format json output programatically in javascript/typescript

2 Answers2