如何从JSON中提取值

Using node.js 6.10

使用node.js 6.10

console.log("returned data1 " + body);
// returns: returned data1 "{'response' : 'Not latest version of file, update not performed'}"

I want to extract the Not latest version of file, update not performed and place it into the valueReturned var. I have tried

我想提取不是最新版本的文件，更新未执行并将其放入valueReturned var。我努力了

    var jsonBody = JSON.parse(body);
            var valueReturned = jsonBody["response"];
            console.log("logs: " + valueReturned);
// returns: logs: undefined

does anyone know where I am going wrong?

有谁知道我哪里出错了？

ThankYous

3 个解决方案

#1

You need a valid JSON string to parse JSON.

您需要一个有效的JSON字符串来解析JSON。

let body = "{ \"response\" : \"Not latest version of file, update not performed\"}";
let jsonBody = JSON.parse(body);
let valueReturned = jsonBody.response;
console.log("logs: " + valueReturned);

#2

The problem is body is not a valid JSON format. The key and value should be wrapped in a double quotes("). Otherwise the code should work as shown below:

问题是body不是有效的JSON格式。键和值应该用双引号（“）包装。否则代码应该如下所示：

const body = '{ "response" : "Not latest version of file, update not performed" }';

console.log("returned data1 " + body);
// returns: returned data1 "{'response' : 'Not latest version of file, update not performed'}"

var jsonBody = JSON.parse(body);
var valueReturned = jsonBody["response"];
console.log("logs: " + valueReturned);
// returns: logs: undefined

#3

A hacky and unreliable method if you have to deal with your body as is would be to manually transform it into JSON format and then parse it:

如果你必须处理你的身体，那么一种hacky和不可靠的方法是手动将其转换为JSON格式然后解析它：

const body = `"{'response' : 'Not latest version of file, update not performed'}"`;
const formattedBody = body
  .slice(1, body.length - 1)
  .replace(/'/g, '"');
const obj = JSON.parse(formattedBody);
console.log(obj.response);

#1