'Why we didn't use * during dereferencing the pointer?
In the below code, we get a pointer from strdup(source) and we store it in a pointer named target. Now, when we print the string using pointer, we don't add * at the beginning of the pointer: why is it so? As I studied whenever we want to dereference any pointer we use *pointer_name. If we add * in the below code, we get an error. I am very beginner, so pls ans in easy words.
#include<stdio.h>
#include<string.h>
int main()
{
char source[] = "Programming";
char* target = strdup(source);
printf("%s\n",target);
return 0;
}
Solution 1:[1]
printf expects a char pointer in the place of the %s specifier.
Solution 2:[2]
char* target = strdup(source);
printf("%s\n",target);
Why we don't use *target in the code above?
The explanation is quite simple, as already stated in previous answers: target has type char pointer, which is exactly what printf() wants in the above call.
Now, printf() is a little complicated because its semantic is not simple - basically it accepts zero or more arguments after the first, of any type (possibly applying promotion). But if we use strdup() again, maybe it is simpler:
char* target2 = strdup(target);
Here, if you wrote strdup(*target), the compiler might warn that you are passing a char instead of a pointer to char.
Solution 3:[3]
strdup() returns a char*, hence the char* type of target. target holds a pointer to the first character in an array of chars. printf("%s", string) expects string to be a char*, so there’s no reason to do anything to target; just pass it to printf().
If you dereferenced target, you would get a single char (P in this case). printf() would then complain that you had supplied a character instead of a string (pointer to character). Even worse, the program could compile, and then printf() would try to print the string at address P (0x50), which would result in probably unwanted behaviour.
When working with arrays—a string is a type of array—you rarely want to dereference the array.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | bolov |
| Solution 2 | linuxfan says Reinstate Monica |
| Solution 3 |
