Parse Json string to find all values of same element-CodePudding

I have a json as below.

{
    "name": "",
    "id": "test1",
    "properties": {
        "name1": [
            {
                "id": "test2",
            },
            {
                "id": "test3"
                }
            }
        ],
        "name3": [
            {
                "id": "test4"


            }
        ],
        "name5": [
            {
                "id": "test7"
            }
        ],
        "name7": [
            {
                "id": "test8"
            }
        ]
    }
}

In the above JSON. I am looking to extract values of all properties which has "id". so finally I need a list that has id values as below.

{"test2", "test3","test4","test7","test8"}

How I can implement this in C#. Thanks for any suggestions?

CodePudding user response：

Based on your mention of JsonConvert it seems you are using Json.NET. So one of the options is to use json path to extract needed values:

var js_str= ....;
var jToken = JToken.Parse(js_str);  
var result = jToken.SelectTokens("$.properties.*.[*].id")
    .Values()
    .Select(value => value.Value<string>())
    .ToList();

Or you can query you json with LINQ.

Or create model that represents your data. There is quite common convention for dictionaries to represent object so something like this will work:

public class Root
{
    public Dictionary<string, List<Obj>> Properties { get; set; }
}

public class Obj
{
    public string Id { get; set; }
}

var deserialized = JsonConvert.DeserializeObject<Root>(js_str);
var result = deserialized.Properties
    .Values
    .SelectMany(v => v)
    .Select(obj => obj.Id)
    .ToList();

CodePudding user response：

Using JToken.Parse does not need to create the classes, but as I guess you may need not only Ids but some another data too. In this case try this code that is using JsonConvert

var json="{\"name\":\"\",\"id\":\"test1\",\"properties\":{\"name1\":[{\"id\":\"test2\"},{\"id\":\"test3\"}],\"name3\":[{\"id\":\"test4\"}],\"name5\":[{\"id\":\"test7\"}],\"name7\":[{\"id\":\"test8\"}]}}";

var jD=JsonConvert.DeserializeObject<Root>(json);
    
var ids=jD.properties.Select(p =>p.Value.Select(v =>v.id ) ).SelectMany(i=> i).ToList();

output

["test2", "test3","test4","test7","test8"]

classes

public class Root
{
    public string name { get; set; }
    public string id { get; set; }
    public Dictionary<string,Name[]> properties { get; set; }
}
public class Name
{
    public string id { get; set; }
}