R Variables

Creating Variables in R

Variables are containers for storing data values.

R does not have a command for declaring a variable. A variable is created the moment you first assign a value to it. To assign a value to a variable, use the <- sign. To output (or print) the variable value, just type the variable name:

Example

name <- "John"
age <- 40

name   # output "John"
age    # output 40

From the example above, name and age are variables, while "John" and 40 are values.

In other programming language, it is common to use = as an assignment operator. In R, we can use both = and <- as assignment operators.

However, <- is preferred in most cases because the = operator can be forbidden in some context in R.

---

Print / Output Variables

Compared to many other programming languages, you do not have to use a function to print/output variables in R. You can just type the name of the variable:

Example

name <- "John Doe"

name # auto-print the value of the name variable

However, R does have a print() function available if you want to use it. This might be useful if you are familiar with other programming languages, such as Python, which often use a print() function to output variables.

Example

name <- "John Doe"

print(name) # print the value of the name variable

And there are times you must use the print() function to output code, for example when working with for loops (which you will learn more about in a later chapter):

Example

for (x in 1:10) {
  print(x)
}