Defined in header <<fenv.h>>

Comments serve as a sort of in-code documentation. When inserted into a program, they are effectively ignored by the compiler; they are solely intended to be used as notes

Defined in header <stdlib.h>

Usage return statement:

Defined in header <complex.h>

Defined in header <wchar.h>

Defined in header <stdlib.h>

Defined in header <complex.h>

Defined in header <wctype.h>

Executes a statement repeatedly until the value of condition becomes false. The test takes place after each iteration