Character Strings Character strings are handled as primitive or complex depending on the language and the use. At run-time Flexibility only limited by the machine Record Hetergeneous aggregate of data elements in which the elements are identified by names. Records are often defined by structures within or outside a program. Union type Data types are mixed. Free union Type checking is left to the programmer No type declaration.
Type is declared with the data and is easier to type-check.
Modula-2 and Ada use them. Implemented as bit strings in memory. Pointer type The pointer indicates the location of the value in a heap. Heap is where storage is dynamically allocated. Once allocated it is referred to as the heap dynamic variable.