JSON.parse 在我的字符串上返回 undefined

Question

I have a returned string from my server and I want to parse it into a JSON object, the following is the string and what I am doing:

stringToParse = "\"{'female': 16, 'brand': 75, 'male': 8}\""
dataJson = JSON.parse(stringToParse)
console.log(dataJson)
console.log(dataJson.male)

I'm getting this as output:

{'female': 16, 'brand': 75, 'male': 8}
undefined

so I can't access the male, female, and brand objects within the JSON.

Answer 1

There is something wrong with you string I think those extra quotation marks are useless. The JSON parser things that you providing him with a string "{"female": 16, "brand": 75, "male": 8}" and it parses it as string so you see the console.log result {"female": 16, "brand": 75, "male": 8} but it is not an objet the whole thing is a string. Remove extra quotation marks and it will think it is an object.

 stringToParse = '{"female": 16, "brand": 75, "male": 8}' dataJson = JSON.parse(stringToParse) console.log(dataJson) console.log(dataJson.male)

Answer 2

correct json to be parsed should be

stringToParse = '{"female": 16, "brand": 75, "male": 8}'

you need to alter the code at your server to return data in this manner, or handle it in your js file.

This code works

let stringToParse = '{"female": 16, "brand": 75, "male": 8}'
dataJson = JSON.parse(stringToParse)
console.log(dataJson)
console.log(dataJson.male)

If, though, you can't alter the original stringToParse , then try this in order to parse it at js

let stringToParse = "\"{'female': 16, 'brand': 75, 'male': 8}\""
JSON.parse(stringToParse.replace(/\"/g, '').replace(/'/g, '"'))

Answer 3

Your json string is invalid format. In JSON, keys must be strings written with double quotes not in single quotes. eg {"male":16}. Try to read this https://www.w3schools.com/js/js_json_syntax.asp . So below is the correct answer:

stringToParse = '{"female": 16, "brand": 75, "male": 8}'
dataJson = JSON.parse(stringToParse)
console.log(dataJson)
console.log(dataJson.male)

Answer 4

In your second line parse like this

stringToParse = "\"{'female': 16, 'brand': 75, 'male': 8}\""
dataJson = JSON.parse(stringToParse.replace(/\"/g, '').replace(/'/g, '"'))

 stringToParse = "\"{'female': 16, 'brand': 75, 'male': 8}\"" dataJson = JSON.parse(stringToParse.replace(/\"/g, '').replace(/'/g, '"')) console.log(dataJson) console.log(dataJson.male)