/**
* Object Example in TypeScript
* ----------------------------
* Demonstrates:
* - Creating typed objects
* - Accessing properties
* - Updating properties
* - Adding methods
* - Iterating over objects
* - Using Object utility methods
* - Creating reusable functions
*/
/**
* Define the shape of a Person object.
*/
interface Person {
firstName: string;
lastName: string;
age: number;
isEmployed: boolean;
city?: string; // Optional property
}
/**
* Returns a formatted description of a person.
*
* @param person Person object
* @returns Formatted string
*/
function getPersonSummary(person: Person): string {
return `${person.firstName} ${person.lastName} is ${person.age} years old.`;
}
/**
* Returns a new Person object with an updated age.
* Does not modify the original object.
*
* @param person Original person
* @param newAge Updated age
* @returns New person object
*/
function updateAge(person: Person, newAge: number): Person {
return {
...person,
age: newAge
};
}
// ------------------------------------------------------------------
// Create an object
// ------------------------------------------------------------------
const person: Person = {
firstName: "John",
lastName: "Doe",
age: 30,
isEmployed: true
};
console.log("=== Original Object ===");
console.log(person);
// ------------------------------------------------------------------
// Access properties
// ------------------------------------------------------------------
console.log("\n=== Access Properties ===");
console.log(person.firstName);
console.log(person.lastName);
console.log(person.age);
// ------------------------------------------------------------------
// Update a property
// ------------------------------------------------------------------
console.log("\n=== Update Property ===");
const updatedPerson: Person = updateAge(person, 31);
console.log(updatedPerson);
// ------------------------------------------------------------------
// Add optional property
// ------------------------------------------------------------------
console.log("\n=== Add Property ===");
updatedPerson.city = "New York";
console.log(updatedPerson);
// ------------------------------------------------------------------
// Function Example
// ------------------------------------------------------------------
console.log("\n=== Function Example ===");
const summary: string = getPersonSummary(updatedPerson);
console.log(summary);
// ------------------------------------------------------------------
// Object.keys()
// ------------------------------------------------------------------
console.log("\n=== Object.keys() ===");
const keys: string[] = Object.keys(updatedPerson);
console.log(keys);
// ------------------------------------------------------------------
// Object.values()
// ------------------------------------------------------------------
console.log("\n=== Object.values() ===");
const values: unknown[] = Object.values(updatedPerson);
console.log(values);
// ------------------------------------------------------------------
// Object.entries()
// ------------------------------------------------------------------
console.log("\n=== Object.entries() ===");
for (const [key, value] of Object.entries(updatedPerson)) {
console.log(`${key}: ${value}`);
}
// ------------------------------------------------------------------
// Property Checks
// ------------------------------------------------------------------
console.log("\n=== Property Checks ===");
console.log(Object.hasOwn(updatedPerson, "age"));
console.log(Object.hasOwn(updatedPerson, "salary"));
// ------------------------------------------------------------------
// Clone an Object
// ------------------------------------------------------------------
console.log("\n=== Clone Object ===");
const clonedPerson: Person = {
...updatedPerson
};
console.log(clonedPerson);
// ------------------------------------------------------------------
// Freeze an Object
// ------------------------------------------------------------------
console.log("\n=== Object.freeze() ===");
const settings: Readonly<{
theme: string;
language: string;
}> = Object.freeze({
theme: "dark",
language: "en"
});
console.log(settings);
// ------------------------------------------------------------------
// Destructuring
// ------------------------------------------------------------------
console.log("\n=== Destructuring ===");
const {
firstName,
age
}: {
firstName: string;
age: number;
} = updatedPerson;
console.log(firstName);
console.log(age);
/*
run:
=== Original Object ===
{ firstName: 'John', lastName: 'Doe', age: 30, isEmployed: true }
=== Access Properties ===
John
Doe
30
=== Update Property ===
{ firstName: 'John', lastName: 'Doe', age: 31, isEmployed: true }
=== Add Property ===
{
firstName: 'John',
lastName: 'Doe',
age: 31,
isEmployed: true,
city: 'New York'
}
=== Function Example ===
John Doe is 31 years old.
=== Object.keys() ===
[ 'firstName', 'lastName', 'age', 'isEmployed', 'city' ]
=== Object.values() ===
[ 'John', 'Doe', 31, true, 'New York' ]
=== Object.entries() ===
firstName: John
lastName: Doe
age: 31
isEmployed: true
city: New York
=== Property Checks ===
true
false
=== Clone Object ===
{
firstName: 'John',
lastName: 'Doe',
age: 31,
isEmployed: true,
city: 'New York'
}
=== Object.freeze() ===
{ theme: 'dark', language: 'en' }
=== Destructuring ===
John
31
*/
