1. Class, contructing and class methods

library(knitr)
knit("1. Class.Rmd")

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## processing file: 1. Class.Rmd

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## output file: 1. Class.md

## [1] "1. Class.md"

#Install a package R6 name
install.packages("R6")

## Error in install.packages : Updating loaded packages

library(R6)

#Defining a class

Person <- R6Class(
  classname = "Person",
  public = list(
    name = NULL,
    age = NULL,
    desire = NULL,
    
    initialize = function(name = NA, age = NA, desire=NA){
      self$name <- name
      self$age <- age
      self$desire <- desire
      
      self$say_hello()
    },
    
    set_age = function(val){
      self$age <- val
      cat("Age of ", self$naem, " is: ", val, ".\n", sep = "")
    }, 
    
    set_desire = function(val){
      self$desire <- val
      cat("Desire of ", self$name, "is: ", val, ".\n", sep = "")
    }, 
    
    say_hello = function(){
      cat(paste0("Hello, my name is ", self$name, ".\n", "age of ", self$age, ".\n", "desire of ", self$desire, ".\n"))
    }
  )
)

#Inititalizing objects

ho_duc_duy <- Person$new(
  name = "Ho Duc Duy",
  age = "38",
  desire = "Gap in knowledge"
)

## Hello, my name is Ho Duc Duy.
## age of 38.
## desire of Gap in knowledge.

#Getting and setting attributes
ho_duc_duy$set_age(38)

## Age of  is: 38.

ho_duc_duy$age

## [1] 38

ho_duc_duy$age <- 39
ho_duc_duy$age

## [1] 39

hdd <- ho_duc_duy$clone()
hdd$age

## [1] 39

hdd$say_hello()

## Hello, my name is Ho Duc Duy.
## age of 39.
## desire of Gap in knowledge.