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R Introduction: Part II
R Introduction: Part II
Modifying
Now let's move on to list modification tools. First, let's consider methods of adding an element (or elements) to a list.
The first method is convenient for adding single values. You need to assign a new value to the new index or naming. For example, let's add a new element named integer with the value of 23L.
# Creating a list test <- list(text = "Text", number = 42, logical = TRUE) # Add new value test['integer'] <- 23L test # Output modified list
Note
Unlike in the
list()function, you must use quotes for naming while adding a new element. You can also 'merge' two lists by placing them inside a vector. This approach will 'connect' two lists together.
# Two lists list1 <- list("first", 10) list2 <- list("second", 20) # Merge two lists list12 <- c(list1, list2) list12 # Output its value
Also, you can delete elements from the list. To do it, assign to the necessary index value NULL. For example, let's remove TRUE from the first example.
test <- list(text = "Text", number = 42, logical = TRUE) test['integer'] <- 23L # Remove the third element test$logical <- NULL # Output modified list test
As you can see, you removed the TRUE element. Finally, to change the existing value of the list, reassign the new value to the existing index/naming. For example, if you write test[1] <- "word", then instead of "Text", the first element will be "word".
Swipe to start coding
Given list info from the previous chapter. Your tasks are:
- Rewrite the fourth element to
44(this chapter is the 44th). - Remove the third element (which is
1). - Add a new element named
Levelwith the value of'Beginner'. - Output modified list
info.
Løsning
Skift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående mulighederTak for dine kommentarer!
Modifying
Now let's move on to list modification tools. First, let's consider methods of adding an element (or elements) to a list.
The first method is convenient for adding single values. You need to assign a new value to the new index or naming. For example, let's add a new element named integer with the value of 23L.
# Creating a list test <- list(text = "Text", number = 42, logical = TRUE) # Add new value test['integer'] <- 23L test # Output modified list
Note
Unlike in the
list()function, you must use quotes for naming while adding a new element. You can also 'merge' two lists by placing them inside a vector. This approach will 'connect' two lists together.
# Two lists list1 <- list("first", 10) list2 <- list("second", 20) # Merge two lists list12 <- c(list1, list2) list12 # Output its value
Also, you can delete elements from the list. To do it, assign to the necessary index value NULL. For example, let's remove TRUE from the first example.
test <- list(text = "Text", number = 42, logical = TRUE) test['integer'] <- 23L # Remove the third element test$logical <- NULL # Output modified list test
As you can see, you removed the TRUE element. Finally, to change the existing value of the list, reassign the new value to the existing index/naming. For example, if you write test[1] <- "word", then instead of "Text", the first element will be "word".
Swipe to start coding
Given list info from the previous chapter. Your tasks are:
- Rewrite the fourth element to
44(this chapter is the 44th). - Remove the third element (which is
1). - Add a new element named
Levelwith the value of'Beginner'. - Output modified list
info.
Løsning
Skift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående mulighederTak for dine kommentarer!
Skift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder