I want to change the background color of every cell of the second column of the datatable when its value is equal to the value of the cell of the same row of the third column of the dataframe in my shiny app.

## app.R ##
library(shiny)
library(shinydashboard)
library(DT)
comp<-structure(list(Source = c("dates1", "dates2", "dates3", "dates4", 
                                "dates5", "dates6", "dates7"), Counts = c(12L, 15L, 17L, 10L, 
                                                                          12L, 7L, 9L), Comparison = c(15, 15, 15, 15, 15, 15, 15), Difference = c(3, 
                                                                                                                                                   0, -2, 5, 3, 8, 6)), row.names = c(NA, -7L), class = "data.frame")


ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(
    datatableOutput("table")
  )
)

server <- function(input, output) {
  
  output$table<-renderDataTable({
    datatable(comp)
  })
}

shinyApp(ui, server)    

>Solution :

js <- "
function(row, data) {
  if(data[2] == data[3]) {
    $('td:eq(2)', row).css('background-color', 'orange');
  }
}
"

datatable(
  comp, 
  options = list(
    "rowCallback" = JS(js)
  )
)