R Variables: A variable provides a named space for storing values. A variable in R can be stored in a vector or group of vectors, or it can be combined with many R objects. 

An allowable name for the variable includes letters, numbers, dots, and characters underlined. A variable name begins with a letter or a dot followed by no numbers.

Variable allocation

Variables can be used using the left part, the right part, or equal; Assigned to the operator. The values ​​of the variables can be printed using the print() or cat() functions. The cat () function concatenates several items into a single line of continuous output.

# Assignment using equal operator.

var.1 = c (0,1,2,3)

# Assignment using leftward operator.

var.2 <- c (“learn”, “R”)

# Assignment using rightward operator.

c (TRUE, 1) -> var.3

print (var.1)

cat("var.1 is", var.1, "\n")
cat("var.2 is", var.2, "\n")
cat("var.3 is", var.3, "\n")

When the above code is executed, the following output is obtained:

[1] 0123

var.1 is 0123

var.2 is learn R

var.3 is 1 1

Note – Vector (c (TRUE, 1) contains a combination of logic and numeric classes. Therefore, the logic class is corrected to a numeric class and returns TRUE as 1.

One-variable data types

In the programming language R, A variable in itself is not expressed from any data type; Instead, it receives the data type of the object R to which it is assigned.

R is a dynamically typed language, meaning that when using a variable in the program, we can change its data type repeatedly.

var_x <- “Hello”

cat (“The class of var_x is“, class (var_x), ”\ n”)

var_x <- 34.5

cat (”Now the class of var_x is“, class (var_x), ”\ n”)

var_x <- 27L

cat (”Next the class of var_x becomes“, class (var_x), ”\ n”)

When we run the above code, the following result is obtained:

The class of var_x is a character

Now the class of var_x is numeric

Next, the class of var_x becomes an integer

Find Variables

To identify the variables that are currently available in the workspace, we use the Is () function. The Is () function can also use patterns to match the names of variables.

print (ls ())

When we run the above code, the following result is obtained:

[1] “my var” “my_new_var” “my_var” “var.1”

[5] "var.2" "var.3" "var.name" "var_name2."

[9] "var_x" "varname"

Note: This is a sample output, depending on the variables defined in your environment.

This function uses patterns to match variable names.

# List the variables starting with the pattern “var”.

print (ls (pattern = “var”))

When we run the above code, the following result is obtained:

[1] "my var" "my_new_var" "my_var" "var.1"

[5] "var.2" "var.3" "var.name" "var_name2."

[9] "var_x" "varname"

Variables starting with (.) They are hidden (Hayden). They can be listed using the “all.names = TRUE” argument to the Is() function.

print (ls (all.name = TRUE)

When we run the above code,  the following result is obtained:

[1] “.cars” “.Random.seed” “.var_name” “.varname” “.varname2”

[6] “my var” “my_new_var” “my_var” “var.1” “var.2”

[11] ”var.3 ″“ var.name ”“ var_name2. “Var_x"

Clear variables

Variables can be cleared using the rm () function. Next, we present variable var.3. We clean it. An error will occur in the variable value print section.

rm (var.3)

print (var.3)

When the above code is executed, the result is as follows:

[1] "var.3"

Error in print (var.3): object 'var.3' not found

Can be used with the rm() and is () functions; it clears all variables.

rm (list = ls ())

print (ls ())

When we run the above code, the following result is obtained:

character (0)