What is the Best Practice for malloc?

Question

Which if any of the following are correct and would be considered best practice to create a char string capable of holding 100 characters?

char * charStringA         


        

Answer 1

The most general form is:

#include 

typedef struct { int a; char b[55]; } Thing;

Thing *p;
p = malloc (100 * sizeof *p);

This works indepentely of the actual definition of Thing, so if you would "reuse" the line as

Typedef { float water; int fire; } OtherThing;
OtherThing *p;
p = malloc (100 * sizeof *p);

it would still function as intended.

The original case would yield:

char *p;
p = malloc (100 * sizeof *p);

, where the sizeof *p would of course be superfluous (since sizeof(char) == 1 by definition) , but it won't hurt.

BTW: this answer is mostly about style. Syntactically, all variants are acceptible, given you include stdlib.h (or manually introduce a prototype for malloc())