Demo on dynamic number of sliders

server.R

# server.R

shinyServer(function(input, output, session) {
    output$sliders <- renderUI({
        if (is.null(input$n) || is.na(input$n)) {
          n <- 1
        } else {
          n <- round(input$n,0)
        }
        lapply(1:n, function(i) {
          sliderInput(
            inputId = paste0("sliderId", i)
            , label = paste0("Slider", i)
            , min = 0
            , max = 10
            , value = c(0, 2)
            , step = 1
          )
        })
    })
})

ui.R

# ui.R

shinyUI(
  basicPage(
    numericInput(inputId = "n", label = "How many sliders to display?", value = 1)
    ,
    uiOutput("sliders")
  )
)