R select column by name: dataframe$x returns NULL

Question

I have a Data frame that I want to draw all the values out of column by column identified by column name. The code below just returns five NULL values where five is the number of columns in my Data frame

for(x in names(DataFrame)){
  print(DataFrame$x)
}

This is the simplified version, but the ultimate goal is a shiny app that turns individual columns into selectInput boxes with this function. I can then modify the number of input boxes just by changing the spreadsheet. Seen below

for(x in names(DataFrame)){
  fluidRow(
    column(3,
       selectInput(paste("Input","x"), h5("x"),
                   choices= DataFrame$x)))}

In short, I want the DataFrame$x to return a list of the things in each column. Now it's returning NULL.

Wilmar van Ommeren · Accepted Answer · 2019-01-31 12:25:12Z

1

Currently you are trying to print the values in a column named x. If you want to link to a column using a name (string) you should but the string between brackets.

for(x in names(DataFrame)){
    print(DataFrame[[x]])
}

edited Jan 31, 2019 at 12:25

answered Jan 31, 2019 at 12:20

Wilmar van Ommeren

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