Anytime you store a single property for all objects in an array or hash table, so, Fortran, BASIC, APL, Numpy, R, awk, and sometimes Perl. Parallel arrays are

Anytime you store a single property for all objects in an array or hash table, so, Fortran, BASIC, APL, Numpy, R, awk, and sometimes Perl. Parallel arrays are out of style but certainly not unheard of. They're the hot new thing in games programming, under the name "entity-component-system". Even C when `property` is computed rather than materialized. And CLOS even uses that syntax for method invocation. The only language I can think of that uses field(record) syntax for record field access is AT&T-syntax assembly.