How to Add New Property to JSON Object Using JavaScript

// Store JSON string in a JS variable
var json = '{"name": "Harry", "age": 18}';

// Converting JSON-encoded string to JS object
var obj = JSON.parse(json);

// Adding a new property using dot notation
obj.gender = "Male";
    
// Adding another property using square bracket notation
obj["country"] = "United States";
    
// Accessing individual value from JS object
document.write(obj.name + "<br>");    // Prints: Harry
document.write(obj.age + "<br>");     // Prints: 14
document.write(obj.gender + "<br>");  // Prints: Male
document.write(obj.country + "<br>"); // Prints: United States
    
// Converting JS object back to JSON string
json = JSON.stringify(obj);
document.write(json);