# Vector, Array, List and Data Frame in R

Vector, Array, List and Data Frame are 4 basic data types defined in R. Knowing the differences between them will help you use R more efficiently.

1. Vector

All elements must be of the same type.

For example, the following code create two vectors.

```name <- c("Mike", "Lucy", "John")
age <- c(20, 25, 30)
```

2. Array & Matrix

Matrix is a special kind of vector. A matrix is a vector with two additional attributes: the number of rows and the number of columns.

```> x <- matrix(c(1,2,3,4), nrow=2, ncol=2)
> x
[,1] [,2]
[1,]    1    3
[2,]    2    4
```

Similar to matrix, but arrays can have more than two dimensions.

3. List

List can contain elements of different types.

```> y <- list(name="Mike", gender="M", company="ProgramCreek")
> y
\$name
[1] "Mike"
\$gender
[1] "M"
\$company
[1] "ProgramCreek"
```

4. Date Frame

A data frame is used for storing data tables. It is a list of vectors of equal length.

For example, you can create a date frame by using the following code:

```> name <- c("Mike", "Lucy", "John")
> age <- c(20, 25, 30)
> student <- c(TRUE, FALSE, TRUE)
> df = data.frame(name, age, student)
> df
name age student
1 Mike  20    TRUE
2 Lucy  25   FALSE
3 John  30    TRUE
```
Category >> R
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1. gamebusterz on 2016-8-26

Clear and short explanation. Thanks

2. renceokgobja on 2017-6-1

`x <- matrix(c(1,2,3,4), nrow=2, ncol=2)`
``` > x [,1] [,2] [1,] 1 3 [2,] 2 4```
``` > x [,1] [,2] [1,] 1 2 [2,] 3 4```