pointer question

[mouse666666]

i have a question regarding to pointer. i hope someone can explain it to me with basic english please .

for example  1;
 char name[15]={'j','o','h','n'};
char *ptr;

ptr =name; //why dont i need and & sign

for example  ;
 int x=5;
int *t;
t=&x;     // why & here but not in array    
ptr =name; why dont i need and & sign

Also can i point to something that has different types for example char point to int.

[mouse666666]

i have a question regarding to pointer. i hope someone can explain it to me with basic english please .

for example  1;
 char name[15]={'j','o','h','n'};
char *ptr;

ptr = &name; // is this the same as ptr =name
ptr =name; //why dont i need and & sign

for example  ;
 int x=5;
int *t;
t=&x;     // why & here but not in array

Also can i point to something that has different types for example char point to int.

[Adak]

In C, the name of the array, serves as a constant pointer to the base of the array (that's the array[0]). You can't change the address of the array name!

Why wouldn't this work:

int *t;
int n;

t=&n;

t is a pointer, and what do pointers hold as their value? Addresses! And what is &n? The address of n.

Basically, NO, a char pointer shouldn't be used to point to an int. It can be done, but if you want to point to different data types, a void pointer or a pointer that matches that type, is the way to go. A char pointer, for instance, is looking for only 8 bytes, (maybe 16). So it would only "see" 1/2 or maybe 1/4th, of an integer, at that location. (depending on the sizes of char and integer, on your system).

You sound like you want to work with pointers, unions, and casts! They are interesting, for sure.

Good to go?

[JohnGraham]

for example  1;
 char name[15]={'j','o','h','n'};
char *ptr;

ptr = &name; // is this the same as ptr =name
ptr =name; //why dont i need and & sign

for example  ;
 int x=5;
int *t;
t=&x;     // why & here but not in array

You don't need an & sign for "ptr = name" because name is the location of the array (i.e. "name" is where the array is). In this case, "ptr= &name" is just there for ease of use. To get the location of x you need the &, but since the array name is already a location it is not needed.

Also can i point to something that has different types for example char point to int.

Only if you use a union.

[ssharish2005]

This is actually an invalid assignment

ptr = &name; // is this the same as ptr =name

You are assigning pointer-to-Pointer to pointer. Name is already a pointer and assigning a address of a pointer to a variable which is just a pointer. The '*ptr' should have been a pointer-to-pointer to make above assignment. For example

char **ptr;   // pointer-to-pointer to hold the address of pointer
char *ptr1;   // pointer to hold an address
char name[] = "Test string";

ptr = &name;   // assigning address of pointer 'name'. Where 'name' itself is pointing to an array
ptr = name;

ssharish

[ssharish2005]

And I also din't realise this was duplicate post

ssharish

[laserlight]

Threads merged.