Question

Consider the following three, C functions:
[$P_1$]int*g(void);
{
int x = 10;
return(&x);
}
[$P_2$]int*g(void);
{
int*px;
*px = 10;
return px;
}
[$P_3$]int*g(void);
{
int*px;
px=(int*)malloc(size of(int));
*px = 10;
return px;
}
Which of the above three functions are likely to cause problems with pointers?

• A. Only $P_3$
• B. Only $P_1$ and $P_3$
• C. Only $P_1$ and $P_2$
• D. $P_1$, $P_2$ and $P_3$

Answer 1

The correct option is C Only $P_1$ and $P_2$

Function pointers can be useful when we want to create callback mechanism, and need to pass address of a function to another function. They can also be useful when we want to store an array of functions, to call dynamically.

The following three, C functions:
[p1]int*g(void);
{
int x = 10;
return(&x);
}
[p2]int*g(void);
{
int*px;
*px = 10;
return px;
}
[p3]int*g(void);
{
int*px;
px=(int*)malloc(size of(int));
*px = 10;
return px;
}

Output:-

Only p1 and p2.