Shiny delete table row - r

Question

I want to delete the last row of a table using an action button. I have tried to follow this post Shiny: dynamically add/ remove textInput rows based on index
but I don't know how to apply the idea to my particular case.
A minimal reproducible example
library(shiny)
ui <- fluidPage(
sidebarPanel(numericInput("c1","Example", NA),
actionButton("update", "Update Table"),
br(), br(),
actionButton("reset", "Clear")
),
mainPanel( tableOutput("example")
)
)
server <- function(input, output, session) {
# stores the current data frame, called by values() and set by
values(new_data_table)
values <- reactiveVal(data.frame(A=1, B=2, C=3))
# update values table on button click
observeEvent(input$update,{
old_values <- values()
A_new <- input$c1
B_new <- A_new + 2
C_new <- A_new + B_new
new_values <- data.frame(A=A_new, B=B_new, C=C_new)
# attach the new line to the old data frame here:
new_df <- rbind(old_values, new_values)
#store the result in values variable
values(new_df)
#reset the numeric input to NA
updateNumericInput(session, "c1", "Example", NA)
})
#delete last row
deleteEntry <- observeEvent(input$reset,{
#....
})
#Print the content of values$df
output$example <- renderTable({ return(values()) })
}
shinyApp(ui = ui, server = server)
Actually I don't know how to call the last row of my interactive data frame. I have tried something like values() <- values[nrow(values())-1] but it doesn't work. Any suggestion?
EDITED
Following the suggestion below I have modified the deleteEntry function and now it works.
##delete last row
deleteEntry <- observeEvent(input$reset,{
values( values()[-nrow(values()),])
})

Answer 1

To remove the last row of a data.frame as a reactiveVal , use this syntax:
values(values()[-nrow(values()),])