| `%d` | Decimal representation: Display a value as a base 10 (hence the decimal) integer. |
| `%f` | Fixed point decimal representation. Specify the number of places to round to by adding a decimal and a number, eg `%.2f` would round to two decimal places. |
`X`: The type of format to use, and the end of the specifier. Use `d` for integer base 10 (decimal) representation, `f` for fixed point decimal, and `e` for exponential notation, and `g` to select between fixed point and exponential, whichever is shorter.
## `printf`
Write a string to standard output. `f` indicates that it's a formatting string. The string will not include move the cursor to a newline, append `\n` to the end of the string to do so.