通过“ \\” Node.js分割字符串

Question

Hy everyone, I'm having some issues with split a string because when I log her value seems ok but in the final result appears "\\" like,

"map":"{\"isRoot\": true, \"visible\": true}" instead of have "map":"{"isRoot": true, "visible": true}"

So I have this code

if(mapData!=undefined){
    var map = mapData.map;
    console.log("sendDeviceInfo getServicesMapInfoById map  >>>>>>>>>>>>>>>>>>>>> ", map);
    sendData.map=map;
    createLog('debug', __dirname, __filename.slice(__dirname.length + 1, -3), device.id, 'sendDeviceInfo','sendData.map 1', sendData.map);
}

And my logs:

sendDeviceInfo getServicesMapInfoById map  >>>>>>>>>>>>>>>>>>>>>  {"isRoot": true, "visible": true}
4|wscontro | [2017-05-30 12:36:03.010] - debug: /opt/wscontroller/wscontroller-service/scripts/gps GpsController 58a8c61b-f11d-4874-91df-3a5205e4145f sendDeviceInfo sendData.map 1 "{\"isRoot\": true, \"visible\": true}"

Why is this happening?

--- solution

if(mapData!=undefined){
    var map = mapData.map;
    var aux = map.split('\\').join('');
    var jsonObject = JSON.parse(aux);
    sendData.map = jsonObject;  
}

Answer 1

You can replace them like this

yourJsonString = yourJsonString.split('\\').join('');
var jsonObject = JSON.parse(yourJsonString);

Answer 2

That's nothing to worry about. That "\\"s don't actually exist in the string.

When you use JSON.stringify in node.js, the result always has "\\"s to escape special characters, and double quotes are special characters. That character is the unix escape character. That's why it appears kind of everywhere.

Answer 3

尝试使用以下代码删除转义序列

mapData = mapData.replace(/\\"/g, '"');

Answer 4

Your Json string is using "-marks. Since Json is a string itself, we need a solution to tell the compiler which "-marks are marking the string, and which "-marks are part of the string itself.

To do this it's very common among languages to use the -character, and by typing for instance \\", you're 'escaping' the "-mark.

Imagine a string like this: He said to me: "Hi there". Now if we want to make this into a string we could try "He said to me: "Hi there".", though the compiler will see 2 strings and a lost period, because it does not distinguish between the start and end of the string, and the "-marks that are part of the content itself.

When you console.log() an actual string, it will not show the "-marks that show the start and end of the string, because it is not necessary. Because of that, there is no need to escape the "-marks in the string itself.

Whatever the createLog() function does, it apparently needs to note the string down as it being an actual string, and therefor it needs to escape the "-marks with a '\\' sign.