Append multiple JSON arrays and create a new consolidated JSON array

Question

In a file path, I have a few JSON files and I'm trying to consolidate them into one file using Newtonsoft.Json.

JSON1:

[
    {
        "name": "name1",
        "salary": 65000
    }, 
    {
        "name": "name2",
        "salary": 68000
    }
]

JSON2:

[
    {
        "name": "name3",
        "salary": 56000
    }, 
    {
        "name": "name4",
        "salary": 58000
    }
]

JSON3:

[
    {
        "name": "name5",
        "salary": 76000
    }, 
    {
        "name": "name6",
        "salary": 78000
    }
]

JSON4:

[
    {
        "name": "name7",
        "salary": 86000
    }, 
    {
        "name": "name8",
        "salary": 88000
    }
]

When I use the below code, I get the resulting file like below.

Code:

// List to store all the json objects
List<object> combinedJsonObjects = new List<object>();

// Load and append the JSON files
foreach (string filePath in jsonFilePaths)
{
    string jsonContent = File.ReadAllText(filePath);
    object jsonObject = JsonConvert.DeserializeObject(jsonContent);
    combinedJsonObjects.Add(jsonObject);
}

// Serialize the appended JSON objects
string combinedJson = JsonConvert.SerializeObject(combinedJsonObjects, Newtonsoft.Json.Formatting.Indented);

// save JSON file
string combinedJsonFilePath = @"C:\filePath\new.json";
File.WriteAllText(combinedJsonFilePath, combinedJson);

Result:

[
    [
        {
            "name": "name1",
            "salary": 65000
        }, 
        {
            "name": "name2",
            "salary": 68000
        }
    ],
    [
        {
            "name": "name3",
            "salary": 56000
        },
        {
            "name": "name4",
            "salary": 58000
        }
    ],
    [
        {
            "name": "name5",
            "salary": 76000
        },
        {
            "name": "name6",
            "salary": 78000
        }
    ],
    [
        {
            "name": "name7",
            "salary": 86000
        },
        {
            "name": "name8",
            "salary": 88000
        }
    ]
]

But, when the multiple JSON files are consolidated I want the file to look like the below.

Desired Result:

[
    {
        "name": "name1",
        "salary": 65000
    },
    {
        "name": "name2",
        "salary": 68000
    },
    {
        "name": "name3",
        "salary": 56000
    },
    {
        "name": "name4",
        "salary": 58000
    },
    {
        "name": "name5",
        "salary": 76000
    },
    {
        "name": "name6",
        "salary": 78000
    },
    {
        "name": "name7",
        "salary": 86000
    },
    {
        "name": "name8",
        "salary": 88000
    }
]

Answer 1

Try working with collection of JObject's:

List<JObject> combinedJsonObjects = new List<JObject>();

// Load and append the JSON files
foreach (string filePath in jsonFilePaths)
{
    string jsonContent = File.ReadAllText(filePath);
    object jsonObject = JsonConvert.DeserializeObject<JObject[]>(jsonContent);
    combinedJsonObjects.AddRange(jsonObject);
}

// Serialize the appended JSON objects
string combinedJson = JsonConvert.SerializeObject(combinedJsonObjects, Newtonsoft.Json.Formatting.Indented);

// save JSON file
string combinedJsonFilePath = @"C:\filePath\new.json";
File.WriteAllText(combinedJsonFilePath, combinedJson);

Otherwise serializer will procees the whole JSON tree as a new element of the resulting collection (as you see in the resulting output).