A name that starts with an uppercase letter.

A name that uses reserved words like if or TRUE.

A name that includes underscores or periods.

A name that begins with a dot followed by a letter.

A name that includes numbers after the first letter.

totalsales

total.sales

TotalSales2025

TOTAL_SALES

total_sales

To remove errors from the chunk.

To suppress both code and output.

To show only the output, not the code.

To prevent code from running.

To hide warnings.

Logical OR takes precedence over AND, so it's evaluated as A & (B | C).

R always evaluates logical operations in alphabetical order.

The expression is evaluated left to right with equal precedence.

Logical AND takes precedence over OR, so it's evaluated as (A & B) | C.

Parentheses are needed, otherwise, R throws an error.

Modulus (%%)

Logical AND (&)

Addition (+)

Subtraction (-)

Exponentiation (^)

Grouping related code blocks with whitespace.

Using consistent indentation levels.

Using meaningful, descriptive variable names.

Keeping lines under 80 characters.

Avoiding comments for simplicity.

The value 5 is assigned to both x and y, and the expression returns 5.

Only the inner assignment is executed. 

This causes an infinite loop.

R throws a syntax error.

The logical is coerced to 1 or 0 depending on its value.

The logical value is ignored.

R throws a type mismatch error.

The logical is rounded to the nearest integer.

The logical becomes a character string.

Inside the system root directory.

In the same folder as analysis.R.

Inside project/R/data.

Two levels up from the current file.

One level above, inside the project/data folder.

A data frame is a special kind of list.

You can access columns using the $ operator.

Each column must have the same number of rows.

All columns must be numeric.

Each column can be a different data type.