R Variables: A variable provides us with a named space where we can write our programs. 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, including letters, numbers, and dots or characters underlined, is. 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 () function or the cat () function. The cat () function combines several items in the continuous print 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.
So, R is called a language that is typed dynamically, which means that when using a variable in the program, Time and Time again we can change the data type of the same variable.

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 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 is a function that can use patterns to match the names of variables.

# 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 have the variable var.3. We clean. 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 together with the function () rm and () Is; Clear all variables.

rm (list = ls ())

print (ls ())

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

character (0)