Example 1 125 int x 100 sub 1

Example 1 125 int x = 100; sub 1 (&x); passing the address of x void sub 1 (int *pint) { *pint = *pint + 25; } x pint or de-referenced value of pint is the value of what pint points to pint &x 100

Example 2 125 int x = 100; int *p = &x; sub 1 (p); passing the value of p which is the address of x void sub 1 (int *pint) { *pint = *pint + 25; } de-referenced value of pint is the value of what pint points to 100 x pint p

Example 3 125 int x = 100; int *p = &x; sub 2 (&p); passing the address of p void sub 2 (int **ppint) { **ppint = **ppint + 25; } p ppint double de-referenced value of ppint is the value of what ppint points to 100 x

Example 4 int x = 100; int *p = &x; sub 2 (&p); passing the address of p void sub 2 (int **ppint) { *ppint = malloc(sizeof(int)); **ppint = 50; p ppint } single de-referenced value of ppint is the value of what ppint points to. In this case, we are assigning a value to what ppint points to. 100 x double de-referenced value of ppint is the value of what ppint points to 50 malloc-ed

Example 5 int x = 100; int *p = &x; sub 2 (&p); passing the address of p void sub 2 (int **ppint) { ppint = malloc(sizeof(int)); *ppint = 50; p ppint } no de-referencing !! What is this changing? ppint itself 100 x single de-referenced value of ppint is the value of what ppint points to 50 malloc-ed