Editing BASIC09 (section)

===Data types===
BASIC09 included several built-in data types. In addition to the traditional string (STRING) and 40-bit floating point (REAL) types found in most BASICs of the era, it also included the 16-bit signed INTEGER, the 8-bit unsigned BYTE, and the logical BOOLEAN type. The BOOLEAN types were not [[Data structure alignment|packed]] into bytes, a single BOOLEAN used an entire 8-bit byte to store a single value. The language provided separate bytewise [[boolean function|boolean operators]] for bitwise operations on BYTEs and INTEGERs.{{sfn|Manual|1984|pp=7.2-7.6}} In contrast to other BASICs that also operated different base types, BASIC09 did not "decorate" the variable name to indicate the type, and instead used the <code>DIM</code> for definitions; for instance, <code>DIM a,b:BOOLEAN</code> to declare two BOOLEAN variables, or <code>DIM c(5):INTEGER</code> for an array of five INTEGERs.{{sfn|Manual|1984|p=7.6}}

Additionally, BASIC09 included the <code>TYPE</code> keyword, which allowed compound types to be defined, with each "element" listed on a single line separated by semicolons. For instance:{{sfn|Manual|1984|p=7.8}}

 TYPE employee_record=name:STRING;number(2):INTEGER;former:BOOLEAN

defines an employee record type named <code>employee_record</code> with three elements, <code>name</code>, <code>number</code> and <code>former</code>. The employee_record type can now be used in a definition like any other type, for instance, <code>DIM employees(100):employee_record</code>, which defines an array of 100 employee_record's. The elements are accessed in code using dot notation, for instance, <code>employees(50).name="Bob"</code>.{{sfn|Manual|1984|p=7.8}}