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R Variables

Bind clear names to values and understand later reassignment.

How it works

A variable name refers to a value in an environment. Choose names that describe units or roles, such as session_minutes. R permits several naming styles; simple letters, digits and underscores are usually easiest to read. Reassignment changes the current binding. A chained assignment is possible, but separate statements are clearer when the values have different meanings.

Run this R example

These examples run locally with R, not PHP, Python or JavaScript. The reviewed baseline is R 4.5.2 on Windows x64/UCRT, using only packages shipped with R. This is a tested version, not a newest-release claim. Install your own R from the official R project; an IDE is optional. Save the complete source as variables.R in a separate learning folder and run Rscript --vanilla variables.R. Keep code and fictional fixtures separate from a real project.

Bhylu has no R browser runner. There is no Try in playground link because the existing Python and JavaScript editors do not execute R. No package installation, account, network dataset, Apache, MySQL or PHP setting is needed to run these base-R sources.

The complete download uses a local scope, restores its temporary options and treats unexpected warnings as errors. Examples that handle an expected warning do so narrowly. Random examples change only their R process’s RNG state. File examples own their temporary output; figure examples leave their named PNG in the current learning folder and refuse to overwrite it. Use a new empty folder to rerun a figure.

Download the complete variables.R · Download all source files with hash checks

For the optional collection downloader, save download-examples.mjs in an empty folder and run node download-examples.mjs. Local preview before publishing uses node download-examples.mjs http://127.0.0.1:8000/examples/r/. It refuses an existing bhylu-r-examples folder and does not install or execute R.

Example

variables.R

local({
  previous_options <- options(warn = 2, digits = 8, stringsAsFactors = FALSE)
  on.exit(options(previous_options), add = TRUE)
  east_visits <- 8
  west_visits <- 12
  total_visits <- east_visits + west_visits
  label <- paste("Total", total_visits, "visits")
  cat(label, "\n")
  east_visits <- 9
  cat("stored total:", total_visits, "\n")
  invisible(NULL)
})
Focus on the lesson operations

This excerpt omits the complete script’s option/resource setup. Use the full download to execute it.

Operation excerpt

east_visits <- 8
west_visits <- 12
total_visits <- east_visits + west_visits
label <- paste("Total", total_visits, "visits")
cat(label, "\n")
east_visits <- 9
cat("stored total:", total_visits, "\n")

Expected result

Total 20 visits
stored total: 20

total_visits stores the earlier calculated value; it is not a spreadsheet formula automatically recalculated after east_visits changes. paste joins formatted elements into text. The explicit names make it easier to notice an accidental unit mix.

For API behaviour, consult the official Introduction to R and your installed help pages. These small examples do not establish real-world statistical conclusions or production performance.

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