Devlog - 2025年11月12日

🚀 What I Did

• Some lab work on boolean and numbers.

🧠 What I Learned

Objects in JS

const exampleObject = {
 propertyName: value;
}

• To access most common is dot notation objectName.propertyName.

// bracket notation
const person = {
 name: "Alice",
 age: 30,
 city: "New York"
};
console.log(person["name"]); // Alice
console.log(person["age"]); // 30

• Functions and object methods are both ways to encapsulate reusable code.
• Object() - when you want to create an object wrapper for a primitive value.
• Recipe Tracker.

JSON

• JSON - javascript object notation.
• Is a lightweight data format used for data exchange between servers and web applications.

{
 "name": "Alice",
 "age": 30,
 "isStudent": false,
 "list of courses": ["Mathematics", "Physics", "Computer Science"]
}

• JSON.stringify() is used to convert a JavaScript object into a JSON string.

const developerObj = {
 firstName: "Jessica",
 isAwesome: true,
 isMusician: true,
 country: "USA",
};
// result: {"firstName":"Jessica","country":"USA"}
console.log(JSON.stringify(developerObj, ["firstName", "country"]));

• Also accepts an optional parameter called a replacer, which can be a function or an array.
• JSON.parse() converts a JSON string back into a JavaScript object.

const jsonString = '{"name":"John","age":30,"isAdmin":true}';
const userObject = JSON.parse(jsonString);
console.log(userObject);
// Result:
// { name: 'John', age: 30, isAdmin: true }

• Optional chaining operator - ?. is a useful tool in JavaScript that lets you safely access object properties or call methods without worrying whether they exist.

🔥 What’s Next

• Objects.