C Language Bank----pointers

1. If f is a function, please explain the meaning of f () and F.

F is the address of the function, and F () is the function

2. How to understand the subscript operation of arrays?

First, offset, and then take the address.

3.int *p,*q; int a[]={10,20,30,40};  p=&a[0]; q=&a[3]; Excuse me, how much q-p equals?

%p Output is 3

%d output is 12

4. Please explain the difference between int aa (char s[]) and int aa (char *p)?

There is no difference in usage, S "" is just a reminder of the contents of the declaration as an array

5.char *p,*q;   p= "XYZ"; Q=p; May I ask Q=p; Does the assignment statement copy the characters in memory?

No

Char p,q;    P= ' a ';  Q=p; May I ask Q=p; Does the assignment statement copy the characters in memory?

Has PQ as a character variable, not a pointer

6.int a[]={1,2,3,4}; a++: Is the above statement feasible? If this is not possible, please indicate the error.

No, the address of a-headed element cannot be changed.

7.int a[]={1,2,3,4}; int *p=a+1; p++; Is the above statement feasible? If this is not possible, please indicate the error.

OK

8. How do I print out the address of the pointer?

printf ("%p\n", p);

9.int *p,**q,a=6; p=&a; q=& (&a); Is the above statement feasible? If not, please indicate the error.

No, the variable can not be taken two times address, the address does not occupy additional memory space

10. May I ask int *p; *p=10; Is the above statement correct? If the error, please indicate the error.

Not correct, *p does not point to the content

11. What is the meaning of int *p=null?

P does not have any pointing

12. Is the memory allocated when the variable is defined or when the variable is assigned?

assignment when assigning a value

13.char *p= "abcdef"; What do you mean, p[3]?

P Backward offset 3 units after indirect reference

14.char *p= "abcdef";  float *pip=3.134; Is the above statement correct? If wrong, please correct it.

Pointer is an address variable

15.char *p= "ABCD"; *p= ' B '; Is the above statement correct? If the error, please explain why.

Incorrect, cannot change the contents of a string constant

16. Define int a[10] in a file; Is it possible to declare extern int a[] In another file;(unspecified length)?

17.char c[]= "ABCDEFG"; void Fun (char ca[10]) {}; Call the function. Excuse me, is &c and &ca equal?

The actual parameters and formal parameters, the address is not the same, but the same content

are ++CA and &c[1] equal?

Not equal

is &ca[1] and &c[1] equal?

Not equal

is C and &c equal?

Equal, C is the first address of the string constant

18.int *p,a[10]={0}; For (P=&a[9];p >=&a[0];p-) {*p=1;} is there a problem with the above statement?

No

19.char *p= "ABCD";   Char c[]= "ABCD"; *p= ' B ' c[0]= ' B ' is the above statement correct?

The contents of the *p point to a string constant that cannot be changed, and the contents of C "0" can be changed

20.char a[][10]={"ABCD", "AAAA"}; Char b[2][]={"ABCD", "AAAA"}; is the above statement correct?

Incorrect, two-dimensional array B does not have a type defined

C Language Bank----pointers