2. R Objects

## 2.1 Object Assignment

1. Write R code to assign the value 20 to the name `num_1`.

2. Which of the following is a valid object name in R?

- `2.True`
- `else`
- `I_am_not_a_valid_name`
- `I_am_a_Pretty#_name`

3. Write R code to get the list of all objects in the environment.

## 2.2 Numeric Vector, Character Vector, & Logical Vector

1. Write R code to create a numeric vector named `vec_1` with values (7, 24, 8, 26), get its length, and find out its type.

2. Write R code to create a character vector named `char_1` with values (“I”, “am”, “learning”, “R!”), get its length, find out its type, and concatenate the vector into a single string with space as the separator.

3. For the `char_1` defined in Q2, find the number of characters in each string, and convert each string to upper case.

4. Create a length-2 logical vector representing whether `vec_1` and `char_1` are of character type.

5. Let `class1 <- c(7, TRUE)`. Which of the following is the class of `class1`?

- numeric
- logical
- character

6. Let `class2 <- c(7, TRUE, "char")`. Which of the following is the class of `class2`?

- numeric
- logical
- character

## 2.3 Create Vectors with Patterns

1. Write R code to create consecutive integers from -10 to 10.

2. Write R code to create a decreasing sequence from 5 to 1 with increment -0.5.

3. Write R code to create an equally-spaced sequence from 2 to 6 with length 10.

4. Write R code using `rep()` function to create the string

`c("sheep","pig", "cat","sheep","pig", "cat","sheep","pig", "cat")`

5. Write R code using `rep()` function to create the string

`c("sheep","sheep","pig","pig","pig","pig","cat","cat","cat")`

## 2. R Objects