使用 JSON.Parse Reviver 转换 object

Question

Would it be possible to use the reviver on the JSON.parse function in order to change the structure of the data being parsed?

For example, how can I parse the string below:

fruitString = "{"Apple":2,"Orange":4}";

to the following object?

 fruitPrices: { "Apple":{ "price": 2 }, "Orange":{ "price": 4 } }

What I've tried is:

 let fruitPrices = JSON.parse(fruitString, (key, value) => { return {key: {'price' => value}}; });

But what I'm getting is:

>      fruitPrices:{
>         key:{
>            price:{
>               Apple:{
>                  key:{
>                     price:2
>                   }
>                }
>               Orange:{
>                  key:{
>                     price:4
>                   }
>                }
>             }
>           }
>        }

Please may you help me understand what I'm doing wrong?

Answer 1

Here's how you'd do it with a reviver:

let fruitPrices = JSON.parse(
    fruitString,
    (key, value) => key === '' ? value : {price: value}
);

That check against empty string is caused by how the reviver walks through the object. The last iteration happens to take your final object and the key for that final check is always an empty string. We don't want to change anything in that final step, so we just return value there.

Answer 2

No need to wrap with key. https://jsbin.com/pajosorapa/1/edit?html,js,output

 var fruitString = "{\"Apple\":2,\"Orange\":4}"; var fruitPrices = JSON.parse(fruitString, (key, value) => { if (typeof(value) === 'number'){ return { 'price': value }; } return value; }); console.log(JSON.stringify(fruitPrices));