61 lines
2.0 KiB
Markdown
61 lines
2.0 KiB
Markdown
---
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title: Objects in R
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---
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## Objects
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R allows the user to save the data by storing it inside an object.
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## What’s an object?
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An object is a name that you can use to call up stored data. For example, you can save data into an object like a or b.
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```r
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> a <- 5
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> a
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[1] 5
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```
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There are many types of objects in R. Two of the most common are as lists and functions.
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Example of a list:
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```
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> a <- list(1, "Hello, world!", FALSE)
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```
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Lists can contain mixed types of data (number, string and boolean in this example).
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There are many built in functions in R. The user can also make a 'user defined' function, as you see below.
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The following creates the function circleArea that calculates the area of a circle (A = π r2).
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```
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>circleArea <- function(r){
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A <- pi * r^2
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return(A)
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}
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```
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## How to create an Object in R?
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1. To create an R object, choose a name and then use the less-than symbol, `<`,
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followed by a minus sign, `-`, to save data into it. This combination looks like an
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arrow, `<-`. R will make an object, give it your name, and store in it whatever
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follows the arrow. You can also use the '=' sign, but this is a less common method to assign a value to an object and generally frowned upon.
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2. When the user calls the object in the console it provides the output on the next line. For example:
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```r
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> die <- 1:6
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> die
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[1] 1 2 3 4 5 6
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```
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3. You can name an object in R almost anything you want, but there are a few rules. First,
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a name cannot start with a number.
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Second, a name cannot use some special symbols, like `^, !, $, @, +, -, /, or *`:
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4. R also understands capitalization (or is case-sensitive), so name and Name will refer to different objects.
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5. You can see which object names you have already used with the function `ls()`.
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## References
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- [Official Docs](https://cran.r-project.org/manuals.html)
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- [Objects in R by r-bloggers](https://www.r-bloggers.com/classes-and-objects-in-r/)
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- [CRAN](https://cran.r-project.org/doc/manuals/r-release/R-lang.html)
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