In this tutorial, we will learn about is.element() function available in base R and use it to check if one or more elements is present in a vector.
Let us create a sample vector in R
example_vector <- c(1, 2, 3, 4, 7, 8)
Our simple vector hs 6 elements.
example_vector ## [1] 1 2 3 4 7 8
If we want to check if a value us present in the vector, we can use is.element() function available in base R using the format
is.element(value, example_vector)
And if the vector contains the value, we get TRUE as a result and FALSE as result if the vector does not contain the value.
In our toy example, if we check if value 1 is in the vector, we will get TRUE as result.
is.element(1, example_vector) ## [1] TRUE
If we test for a value that is not present in the vector, we will get FALSE as result.
is.element(10, example_vector) ## [1] FALSE
We can use is.element() function to test of multiple values are present in the vector of interest. Here, we ask if the vector contains values 1 and 2. And since both the values are present, we get a vector with two TRUE values.
is.element(1:2, example_vector) ## [1] TRUE TRUE
If we test multiple values present in the vector, where some are present and others are not, we get a boolean vector with TRUE/FALSE.
For example, here we ask if the vector contains values 1 and 10. Since the value 1 is present in the vector, we get
is.element(c(1,10), example_vector) ## [1] TRUE FALSE
In addition to is.element() function, we can also use %in% operator to test if one or more elements in a vector. %in% operator has the same functionality
c(10,1) %in% example_vector ## [1] FALSE TRUE
Here are some other examples.
1 %in% example_vector ## [1] TRUE
1:2 %in% example_vector ## [1] TRUE TRUE