Black & White Series

Array and Object Literals

---

Array Literal

---

Array Literal Use

[<value1>, ..., <valuen>]

const daysOfWeek = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
const day = Math.trunc(Math.random() * 7)
console.log('Weekday: ' + day + ' - ' + daysOfWeek[day])
console.log(daysOfWeek)

Weekday: 0 - Mon
["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]

---

Simple Object Literals

---

Object Literal with Array

---

Object inside Object

---

JSON

JavaScript Object Notation

• Open object exchange standard
• Based on JavaScript object literal
• Incorporated into ECMAScript (2011)
• Adopted by several languages
  • http://json.org/

---

Object Literal

{
  <attr1>: <value1>
  ...
  <attrn>: <valuen> 
}

• <attr>
  • without quotes - as a variable name
  • with quotes - any valid string
    • JSON requires quotes

---

Object Literal

{
  <attr1>: <value1>
  ...
  <attrn>: <valuen> 
}

• <value>
  • any literal
    • number, string, array, or another object

---

Example - Dot Notation

const author = {
  name: 'Asdrubal',
  age:  25
}
console.log(author.name)
author.age = 30
console.log(author)

Asdrubal
{name: "Asdrubal", age: 30}

---

Example - Bracket Notation

const author = {
  name: 'Asdrubal',
  age:  25
}
console.log(author['name'])
author['age'] = 30
console.log(author)

Asdrubal
{name: "Asdrubal", age: 30}

---

Object as a Dictionary

const author = {
  'First Name': 'Asdrubal',
  'Last Name': 'Montequio'
}
console.log(author['First Name'])

const ln = 'Last Name'
author[ln] = 'Capuleto'
console.log(author)

Asdrubal
{First Name: "Asdrubal", Last Name: "Capuleto"}

---

References

• Mozilla MDN - https://developer.mozilla.org

• Eloquent JavaScript - https://eloquentjavascript.net/

---

André Santanchè

www.ic.unicamp.br/~santanch/

Web2Learn

santanche.github.io/web2learn/