REGEX FOR FETCHING JSON DATA-CodePudding

I have a JSON file abc.json

{"value1":5.0,"value2":2.5,"value3":"2019-10-24T15:26:00.000Z","modifier":[],"value4":{"value41":{"value411":5,"value412":"hey"}}}

I can get value2 using this regex

sed -E 's/."value2":"?([^,"])"?.*/\1/' abc.json

I want to know how I can get values of value411 and value412

I don't want to use jq or any other tool as my requirement is to use regex for this.

CodePudding user response：

You should always try to use an existing parser, depending on what platform you work on there should be one that can interpret the data model for you.

I refer to this famous answer about parsing HTML with regex

CodePudding user response：

   var jData = {
        "value1": 5.0,
        "value2": 2.5,
        "value3": "2019-10-24T15:26:00.000Z",
        "modifier": [],
        "value4": {
            "value41": {
                "value411": 5,
                "value412": "hey"
            }
        }
    };

If You try with regex then use this:

JSON.stringify(jData).match(/(?<=(\"(value411|value412)\"\:))[\"\w ] /g)
// Output: ['5', '"hey"']

Demo: https://regex101.com/r/c3K4cH/1

Limitation: You have to put only the key name, don't try to fetch the full object

You create a javascript function get any non-empty value from a JSON, as follows:

function getData(obj, fKey, fData = null) {
    for (const prop of Object.getOwnPropertyNames(obj)) {
        if (!fData) {
            if (typeof obj[prop] === 'object' && Object.keys(obj[prop]).length > 0 && prop !== fKey) {
                return getData(obj[prop], fKey, fData)
            } else {
                if(prop === fKey) {
                    fData =  obj[prop];
                    return fData
                }
            }
        } else {
            return fData;
        }
    }
}

console.log(getData(jData, 'value411'));
console.log(getData(jData, 'value412'));