Extract corresponding numeric values when selecting an input using selectInput-CodePudding

I am trying to make an app using R shiny (see below).

If I select 'Item1', I want the server-side to select the number corresponding to 'Item1' which is 10. Then multiply this value (10) with another number (say 5) and return the output as 'value'. How do I write the server-side code?

Thank you so much.

P.S.: I am a beginner in R


df <- data.frame(item = c('Item1', 'Item2'),
                 value = c(10, 20))
 
ui <- fluidPage(sidebarPanel(selectInput(inputId = 'name',
                            label = 'select item:',
                            df$item)),
                textOutput('value') )

CodePudding user response：

You can index into the value column using the name value. For example

server <- function(input, output, session) {
  output$value <- renderText(df$value[df$item == input$name])
}