# Basic Syntax and Variable Types

### Basic Syntax in R

R uses symbols to represent:

• math operations (`+`, `-`, `*`, and `/` and follows the order of operations)
• logical operators (`>`, `>=`,`<`, `<=`, `==`, and `!=`)
• joining logical operators (`&`, `&&`, `|` and `||`)
• object assignment (`<-` or `=`)

The names of objects in R must follow 3 rules:

1. No spaces
2. No symbols other than `.` or `_`
3. Names must begin with a letter
```## Order of operations25+7/4 #26.75(25+7)/4 #8
## AND vs OR5 > 3 && 3 > 4 #FALSE5 > 3 || 3 > 4 #TRUE
```

### Variable Types in R

All objects in R have a variable type. The most common are:

• numeric: the object is a number
• character: the object contains letters
• logical: the object is either `TRUE` or `FALSE`
• `NA`: the object is blank (categorized as logical, but may be part of a character or numeric vector)

We can use the `class()` function on an object to check its variable type.

`class(2000) #numericclass("apple") #characterclass(NA) #logical`