One 、 Array name

// What is the array name ？
// The array name is the address of the first element of the array 
// But there are 2 Exceptions 
//1.sizeof( Array name ) -  The array name represents the entire array  -  It calculates the size of the entire array , Unit is byte 
//2. & Array name  -  The array name represents the entire array  -  It takes out the address of the entire array 
int main() {
    
	int arr[10] = {
     0 };
	printf("%p\n", &arr);// &arr What we get is the address of the array 
	printf("%p\n\n", &arr + 1);

	printf("%p\n", arr);
	printf("%p\n\n", arr + 1);

	printf("%p\n\n", &arr[0]);

	int sz = sizeof(arr);// The array name represents the entire array 
	printf("%d\n\n", sz);

	printf("%p\n", &arr[0]);
	printf("%p\n", &arr);// The array name is the address of the first element 

	return 0;
}

   As can be seen from the figure above , The difference between the first group of addresses is in octal 28, To convert to decimal is to 40, It's an array arr Sum of all element sizes , therefore &arr What we get is the address of the array , The second group of addresses corresponds to the first group , prove &arr What we get is the address of the array ;
   Print out 40, explain sizeof( Array name ) Represents the entire array ,sizeof( Array name ) It calculates the size of the entire array , So the printed value is 40;
   The address number of the last group is the same , Note that the array name is the address of the first element of the array .

Two 、 Arrays as function arguments

   notes ： Bubble sorting idea is to compare two adjacent elements , And may be exchanged .

void bubble_sort(int arr[], int sz) {
    // Shape parameter arr The essence is the pointer 
	// Determine the number of trips 
	int i = 0;
	for (i = 0; i < sz - 1; i++) {
    
		// A bubble sorting process 
		int j = 0;
		for (j = 0; j < sz - 1 - i; j++) {
    
			if (arr[j] > arr[j + 1]) {
    
				// In exchange for 
				int tmp = arr[j];
				arr[j] = arr[j + 1];
				arr[j + 1] = tmp;
			}
		}
	}
}
int main() {
    
	int arr[] = {
     9,8,7,6,5,4,3,2,1,0 };
	// Sort in ascending order  -  Bubble sort 
	// Count the number of array elements 
	int sz = sizeof(arr) / sizeof(arr[0]);

	bubble_sort(arr, sz);
	return 0;
}