How to Use typeof in R: Syntax and Examples

In R, use the typeof() function to find the internal type of any object. Simply pass the object as an argument like typeof(object), and it returns a string describing the object's type.

Syntax

The typeof() function takes one argument, which is the object you want to check. It returns a string that describes the internal type of that object.

• typeof(x): Returns the type of x.

r

typeof(x)

Example

This example shows how to use typeof() on different kinds of objects like numbers, characters, and logical values.

r

num <- 42
char <- "hello"
logic <- TRUE

typeof(num)
typeof(char)
typeof(logic)

Output

[1] "double"
[1] "character"
[1] "logical"

Common Pitfalls

People often confuse typeof() with class(). typeof() shows the low-level type, while class() shows the object's class used for method dispatch. Also, typeof() does not tell you if a number is integer or double unless you explicitly create an integer.

Example of confusion:

r

# Wrong: expecting typeof to show 'integer'
x <- 5
typeof(x) # returns 'double' because 5 is numeric by default

# Right: create integer explicitly
x_int <- 5L
typeof(x_int) # returns 'integer'

Output

[1] "double"
[1] "integer"

Quick Reference

Type	Description
"logical"	TRUE or FALSE values
"integer"	Whole numbers with L suffix, e.g., 5L
"double"	Decimal numbers (default numeric type)
"character"	Text strings
"complex"	Complex numbers with real and imaginary parts
"raw"	Raw bytes
"list"	List of elements
"NULL"	Empty or null object

Key Takeaways

Use typeof(object) to get the internal type of any R object.

typeof() returns low-level types like 'double', 'integer', or 'character'.

Numeric values are 'double' by default unless marked with L for integer.

typeof() differs from class(), which shows the object's class.

Check typeof() when you need to understand the exact storage type.