Objects in Detail

Introduction to Object

An object is a built-in data type for storing key-value pairs. Data inside objects are unordered, and the values can be of any type.

object = {
  property1: value1,
  property2: value2,
  .
  .
  .
  propertN: valueN
}

Accessing, Adding and Updating properties of an Object

There are 2 types of accessing an object properties.

• Dot Notation

• Bracket Notation

• Dot Notation

  The most common way of accessing object properties is through a dot notation. Use a . (dot) followed by the property name to access its value.

• Bracket Notation

  The most preferred way of accessing object values are through bracket notation. It access all types of keys which can be used in objects Eg. Numbers, string (with or without spaces), etc.

Object Methods

JavaScript Objects may have property values that are functions. These are referred to as object nethods. Methods may be defined using anonymous arrow function expressions, or with shorthand method syntax.

Object Built-in-Methods

1. Object.keys()
2. Object.values()
3. Object.entries()
4. Object.freeze()
5. Object.seal()

• Object.keys()

  It creates an array containing the keys of an object.

• Object.values()

  It creates an array containing the values of an object.

• Object.entries()

  It creates a nested array of the key/value pairs of an object.

• Object.freeze()

  It prevents modification to properties and values of an object.

• Object.seal()

  It prevents new properties from being added to an object, but allows the modification of existing properties.