在javascript中获取方括号而不是在json中的卷曲

Question

If I want to update object in elasticsearch script, thus I need to send some weird modification of JSON ( https://discuss.elastic.co/t/updating-an-object-field/110735/2 ). I don't really know what language is that or why would they do that.

For example, if input is

{"id": 2, "name": "John"}

I need the way in javascript to make it

["id": 2, "name": "John"]

First sloultion would be

standardJson.replace('{', '[').replace('}', ']')

However, I am worried about curly brackets inside values, so above solution would override

"name": "{John"

to

"name": "[Jonh"

And I don't want that. In fact, I need to this inside general purporse library, so I can't just hope this case will not happen.

Answer 1

Try this it will only change outer curly braces to brackets.

 let a =`{"id": 2, "name": "{John}" }` console.log(a.replace(/^\\{(.*)\\}$/,"[$1]"));

Answer 2

Explicit approach based on input object parsing with Object.entries and Array.prototype.map :

 const inputData = { "id": 2, "name": "{John}" }; const parsed = `[` + Object.entries(inputData) .map(v => `"${v[0]}": ` + (typeof v[1] === `string` ? `"${v[1]}"` : v[1]) ) .join(`, `) + `]`; console.log(parsed); // ["id": 2, "name": "{John}"]

To handle nested objects, the procedure can be run recursively with additional parsing branch:

 const inputData = { "id": 2, "name": "{John}", "foo": { "bar": "{zoo}" } }; const parse = (data) => `[` + Object.entries(data) .map(v => `"${v[0]}": ` + ( typeof v[1] === `string` ? `"${v[1]}"` : ( typeof v[1] === "object" ? parse(v[1]) : v[1] ) ) ) .join(`, `) + `]`; console.log(parse(inputData)); // ["id": 2, "name": "{John}", "foo": ["bar": "{zoo}"]]

Nested arrays also can be processed in the same way, just need to add 1 more condition branch.

Answer 3

Based on answers posted here, arrived at final solution, that is a more readable and handles some cases not handled in previous answers (booleans, nulls, numbers, undefined, nested arrays etc)

function toElasticStupidJson(data) {
    if(isPrimitive(data)) return primitiveDisplay(data)
    else if(typeof data === 'object') return objectDisplay(data)
}

function objectDisplay(data) {
    let inner = ''
    if(Array.isArray(data)) inner = data.filter(d => d !== undefined).map(toElasticStupidJson).join(', ')
    else inner = Object.entries(data)
        .filter(keyValue => keyValue[1] !== undefined)
        .map(keyValue => {
            return `"${keyValue[0]}": ` + toElasticStupidJson(keyValue[1])
        })
        .join(', ')
    return `[${inner}]`
}

function isPrimitive(value) {
    return typeof value === 'string'
        || typeof value === 'number'
        || typeof value === 'boolean'
        || value === null
}

function primitiveDisplay(value) {
    if(typeof value === 'string') return `"${value}"`
    if(typeof value === 'number') return `${value}`
    if(typeof value === 'boolean') return `${value}`
    if(value === null) return 'null'
}