Specify storage duration and linkage of objects and functions: auto - automatic duration and no linkage register - automatic duration and no linkage; address of this variable cannot be taken static - static duration and internal linkage (unless at block scope) extern - static duration and external linkage (unless already declared internal) _Thread_local - thread storage duration (since C11) Explanation Storage-class specifiers appear in declarations. At most one specifier may

Defined in header <math.h> #define isfinite(arg) /* implementation defined */ (since C99) Determines if the given floating point number arg has finite value i.e. it is normal, subnormal or zero, but not infinite or NaN. The macro returns an integral value. FLT_EVAL_METHOD is ignored: even if the argument is evaluated with more range and precision than its type, it is first converted to its semantic type, and the classification is based on that. Parameters arg - floa