<> one , Character pointer

1. Two ways of writing character pointer
int main() { char ch = 'a'; char*pc = &ch; char*p = "abcdef"; // Add the first character a Put your address in p in
return 0; }
Address symbols can be used , You can also use double quotes with characters , there abcdef Is a constant string , It can't be changed .

<> two , Pointer array

In a nutshell , It's an array of pointers .
int main() { int *arr[10]; char*ch[20]; return 0; }
<> three , Array pointer

It's essentially a pointer
int main() { int a = 10; int *p = &a; char ch = 'w'; char*pc = &ch; int arr[10]
= { 0 }; int(*pa)[10] = &arr; //pa Is a pointer to an array //&arr The array name is the entire array , What we get is the address of the array return 0;
}
Application of array pointer
eg: Print 2D array
1. Array method
void print(int arr[3][5], int r, int c) { int i = 0; for (i = 0; i < r; i++) {
int j = 0; for (j = 0; j < c; j++) { printf("%d", arr[i][j]); printf("\n"); } }
} int main() { int arr[3][5] = { { 1, 2, 3, 4, 5, }, { 2, 3, 4, 5, 6 }, { 3, 4,
5, 6, 7 } }; printf(arr, 3, 5); return 0; }
2. The method of array pointer
void print(int (*p)[5],int r,int c) { int i = 0; for (i = 0; i < r; i++) { int
j= 0; for (j = 0; j < c; j++) { printf("%d ", *(*(p + i) + j)); } } } int main()
{ int arr[3][5] = { { 1, 2, 3, 4, 5, }, { 2, 3, 4, 5, 6 }, { 3, 4, 5, 6, 7 } };
// Two dimensional array parameter transfer , The array name is also the first element address , The first element of a two-dimensional array is the address of the first line // It's the address on the first line printf(arr, 3, 5); return 0; }
By analogy, we can transfer parameters from one-dimensional arrays , It's the first address , Pass to receive with one-dimensional pointer or array , Get a binary array to pass parameters , It's the address on the first line , Receive with array pointer .

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