R Variables – Find all R Variables – Delete an R Variable

R Tutorial – We shall learn about R Variables, how to assign value to a variable, know the data type of variable, find the list of variables and delete some of them if required.

R Variables

Variables are names given to storage locations of data. Once we declare that a variable would hold some specific data, we may access that specific data in the due course of the program using the variable name. In R programming language, any R-Object could be stored in a variable with a name given to the variable.

Rules for writing R Variables

Following are the rules to give a valid name to an R variable.

  • It may contain letters (Examples : x, y, varx, .. )
  • It may contain numbers (Examples : x1, y1, var25x, .. )
  • It may contain special char Dot (.) (Examples : x., y., var.x, .. )
  • It may contain special char Underscore(_) (Examples : x_1, y_2, var_x, .. )
  • The first character in the name could be a letter. (Examples : x, y, varx, .. )
  • The first character in the name could be a dot not followed by a number. (Examples : .x, .y, varx, .. )
  • Reserved words in R could not be used for variables.

Examples for invalid variable names : .2x, tan, er@t

Assign value to R Variable

R Variable can be assigned a value using one of the following three operators :

  1. Equal Operator    =
  2. Leftward Operator <-
  3. Rightward Operator  ->

An example is provided below :

Find all R Variables

When you are running commands in an R command prompt, the instance might get stacked up with lot of variables.

To find all R variables that are alive at a point in R command prompt or R script file, ls() is the command that returns a Character Vector.

Delete an R Variable

rm(variable_name) deletes an R variable from the stack of variables in a running instance.

Conclusion :

In this R Tutorial, we have learnt about R Variables and to assign values to them, to find all R variables and to delete some of them if necessary.