syntatactically correct?

Question

consider the two declarations

void *voidPtr;

char *charPtr;

which of the following assignments are syntactically correct?

(a)charPtr= voidPtr

(b)*charPtr=voidPtr

(c)*voidPtr=*charPtr

(d)voidPtr=charPtr

 

please explain!

Comments

as per my knowledge, option D is correct.

what is the given answer?

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why option a is not correct?

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i didn't found any problem with option a also

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@Shaik Masthan

Shouldn't   A and B should also be correct ?

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@Shiv Gaur

OPTION B should be wrong

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Option B and C are not correct :

because

charPtr is indicates a pointer points to a char.

voidPtr is a pointer points to void ,

since *charPtr is character it will not store an adress of void,

similarlly option C is incorrect

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@balaganesh

what is the answer they provided?

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option D is the answer.

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@balaganesh

i hope they mistakenly type option a

(a) charPtr= voidPtr

instead of 

(a) *charPtr= *voidPtr

if this is the original option, then only Option D is correct,

otherwise option A and Option D , both are correct 

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then what about c)?

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srestha de-referencing void pointer is not allowed so *voidPtr will give error

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you can't directly de-reference the void pointer

correct syntax of option C ===> *(char *)voidPtr=*charPtr

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@MiniPanda any standard resource about it?

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@Shaik

*charPtr= *voidPtr

then how do we dereference a char pointer and assign a void pointer value?

 

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Some interesting facts point 1

https://www.geeksforgeeks.org/void-pointer-c/

 

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*charPtr= *voidPtr

this is incorrect 

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int main() {     int a = 10;     void *ptr = &a;     printf("%d", *ptr);     return 0; }

See this, it gives compiler error

then how d will be correct 

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We are not de-ferencing void pointer in D.. we are just copying the address of a char variable into void pointer..that is allowed

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ok , thank u :)

can u tell me one last thing, where this copying is actually.

I think, I havenot seen this before

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See this..

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can u tell me one last thing, where this copying is actually.

i didn't get it

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@Minipanda

is it like call by reference?

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@Shaik

I mean one memory adress is copying in another pointer variable

where practically we need to do this?

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is it like call by reference?

Yes kind of.. but like in call by ref, the pointer can manipulate the value by de-referencing but in this case we cannot change value of c by *voidPtr.

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where practically we need to do this?

we can use, void pointer for implementing function overloading in C

Answer 1

voidptr = charptr