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Objects in JavaScript are used to store collections of data as key-value pairs. Each key is a string (or symbol), and each value can be any data type, including numbers, strings, arrays, or even other objects. You use objects when you want to represent a single entity with various properties, such as a user with a name, age, and membership status.


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// Creating an object with key-value pairs
const user = {
  name: "Alice",
  age: 28,
  isMember: true
};

// Accessing properties using dot notation
console.log(user.name); // "Alice"

// Accessing properties using bracket notation
console.log(user["age"]); // 28

// Updating a property
user.age = 29;
console.log(user.age); // 29

// Adding a new property
user.email = "alice@example.com";
console.log(user.email); // "alice@example.com"

Arrays and objects are both used to group data, but they serve different purposes:

Arrays are ordered lists accessed by numeric indices and are ideal for collections of similar items, such as a list of names;
Objects, on the other hand, are unordered and use named keys, making them better for representing structured data where each value is associated with a specific property name.

To access or update object properties, you can use either dot notation (object.property) or bracket notation (object["property"]). Dot notation is more concise and commonly used when the property name is a valid identifier. Bracket notation is useful when the property name is dynamic or not a valid identifier.

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Avsnitt 1. Kapitel 8

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Objects


              1234567891011121314151617181920
            
// Creating an object with key-value pairs
const user = {
  name: "Alice",
  age: 28,
  isMember: true
};

// Accessing properties using dot notation
console.log(user.name); // "Alice"

// Accessing properties using bracket notation
console.log(user["age"]); // 28

// Updating a property
user.age = 29;
console.log(user.age); // 29

// Adding a new property
user.email = "alice@example.com";
console.log(user.email); // "alice@example.com"

Arrays and objects are both used to group data, but they serve different purposes:

Arrays are ordered lists accessed by numeric indices and are ideal for collections of similar items, such as a list of names;
Objects, on the other hand, are unordered and use named keys, making them better for representing structured data where each value is associated with a specific property name.

Var allt tydligt?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 8