differences from FORTRAN

C has

• user-defined structures and types
• pointers and pointer arithmetic
• preprocessor & header files
• recursion
• a bible (Kernighan & Ritchie); various well-defined standards

C doesn't have:

• array as a data type (built-in dimensions, slices, etc)
• string as a data type
• exponentiation operator

C functions are call-by-value, rather than FORTRAN's call-by-reference.

C arrays start from 0 rather than 1.

C multi-dimensional arrays are ordered oppositely from FORTRAN counterparts.