Using JSON functions to parse and manipulate JSON data largely depends on the programming language or environment you're working in. Below are examples for several popular programming languages:
1. JavaScript
JavaScript has built-in support for JSON through the JSON object.
Parsing JSON:
const jsonString = '{"name": "Alice", "age": 25}';
const parsedData = JSON.parse(jsonString);
console.log(parsedData.name); // Output: Alice
console.log(parsedData.age); // Output: 25
Manipulating JSON:
parsedData.age += 1; // Increment age
const updatedJsonString = JSON.stringify(parsedData);
console.log(updatedJsonString); // Output: {"name":"Alice","age":26}
2. Python
Python has a built-in json module.
Parsing JSON:
import json
json_string = '{"name": "Alice", "age": 25}'
parsed_data = json.loads(json_string)
print(parsed_data['name']) # Output: Alice
print(parsed_data['age']) # Output: 25
Manipulating JSON:
parsed_data['age'] += 1 # Increment age
updated_json_string = json.dumps(parsed_data)
print(updated_json_string) # Output: {"name": "Alice", "age": 26}
3. Java
In Java, you can use libraries like org.json, Gson, or Jackson.
Parsing JSON with org.json:
import org.json.JSONObject;
String jsonString = "{\"name\": \"Alice\", \"age\": 25}";
JSONObject jsonObject = new JSONObject(jsonString);
System.out.println(jsonObject.getString("name")); // Output: Alice
System.out.println(jsonObject.getInt("age")); // Output: 25
Manipulating JSON:
jsonObject.put("age", jsonObject.getInt("age") + 1);
String updatedJsonString = jsonObject.toString();
System.out.println(updatedJsonString); // Output: {"name":"Alice","age":26}
4. C#
In C#, you can use Newtonsoft.Json (Json.NET) or System.Text.Json.
Parsing JSON using Newtonsoft.Json:
using Newtonsoft.Json;
using System;
string jsonString = "{\"name\": \"Alice\", \"age\": 25}";
dynamic parsedData = JsonConvert.DeserializeObject(jsonString);
Console.WriteLine(parsedData.name); // Output: Alice
Console.WriteLine(parsedData.age); // Output: 25
Manipulating JSON:
parsedData.age += 1; // Increment age
string updatedJsonString = JsonConvert.SerializeObject(parsedData);
Console.WriteLine(updatedJsonString); // Output: {"name":"Alice","age":26}
5. SQL
In SQL databases like PostgreSQL or MySQL, you can use JSON functions to manipulate JSON data at the database level.
PostgreSQL example:
-- Create table with a JSON column
CREATE TABLE users (data JSON);
-- Inserting JSON data
INSERT INTO users (data) VALUES ('{"name": "Alice", "age": 25}');
-- Query and manipulate JSON data
SELECT
data ->> 'name' AS name,
(data ->> 'age')::int + 1 AS incremented_age
FROM users;
Summary
In each programming language, the common tasks involve parsing a JSON string into an object, manipulating that object (e.g., modifying values, adding new fields), and then serializing it back to a JSON string. Make sure to handle any exceptions or errors that may arise during parsing or serialization for robust applications.