JSON Parsing (org.json)

import org.json.*

Key Classes

• JSONArray
• JSONObject

Parsing JSON

• Pass a string with valid JSON format to JSONArray or JSONObject
• Get a value of key with jsonObject[<index>] or jsonObject.get<DataType>
• To get a jsonObject in jsonObject use .getJSONObject(<key>)
• To get a jsonObject in jsonArray use .getJSONObject(<index>)

Get data from a JSON object

val jsonString = """
        {
            "name": "Elias",
            "birthday": "2010-05-15",
            "favorite": "Coding"
        }
    """.trimIndent()

val jsonObject = JSONObject(jsonString)

val name = jsonObject.getString("name")
val birthday = jsonObject.getString("birthday")
val favorite = jsonObject.getString("favorite")

println("Name: $name")
println("Birthday: $birthday")
println("Favorite: $favorite")

Get data from a JSON array

val jsonString = """
        {
            "name": "Elias",
            "hobbies": ["Coding", "Reading", "Writing"]
        }
    """.trimIndent()

val jsonObject = JSONObject(jsonString)

val name = jsonObject.getString("name")
val hobbiesArray = jsonObject.getJSONArray("hobbies")

println("Name: $name")
println("Hobbies:")

for (i in 0 until hobbiesArray.length()) {
    val hobby = hobbiesArray.getString(i)
    println("- $hobby")
}

Create JSON object or array

val name = "Elias"
val age = 14
val hobbies = listOf("Coding", "Reading", "Gaming")

// Create a JSON array from the hobbies list
val hobbiesJsonArray = JSONArray()
for (hobby in hobbies) {
    hobbiesJsonArray.put(hobby)
}

// Create the JSON object and put data into it
val jsonObject = JSONObject()
jsonObject.put("name", name)
jsonObject.put("age", age)
jsonObject.put("hobbies", hobbiesJsonArray)

// Output the final JSON string
println(jsonObject.toString(2)) // Pretty print with 2 spaces