Cursor and Array in C ++

Pointers and Arrays are closely related. In fact, pointers and arrays are interchangeable in some cases. For example, a pointer that points to the array head can access that array using either an arithmetic pointer or an array index. You consider the following example:

 #include using namespace std ; const int MAX = 3 ; int main () { int mang [ MAX ] = { 10 , 100 , 200 }; int * contro ; // chung ta co mot mang dia chi trong con tro. contro = mang ; for ( int i = 0 ; i < MAX ; i ++) { cout << "Dia chi cua mang[" << i << "] = " ; cout << contro << endl ; cout << "Gia tri cua mang[" << i << "] = " ; cout << * contro << endl ; // tro toi vi tri tiep theo contro ++; } return 0 ; } 

Running the above C ++ program will produce the following results:

Cursor and Array in C ++ Picture 1

However, pointers and arrays are not completely interchangeable. For example, consider the following program:

 #include using namespace std ; const int MAX = 3 ; int main () { int mang [ MAX ] = { 10 , 100 , 200 }; for ( int i = 0 ; i < MAX ; i ++) { * mang = i ; // Day la cu phap chinh xac mang ++; // cu phap nay la sai . Ban nen chu y. } return 0 ; } 

Applying the cursor operator * to the bearing variable is perfect, but it is not valid when modifying the bearing variable value. The reason is that the variable is a constant that points to the beginning of the array and cannot be used as l-value.

Because, an array name creates a pointer constant, it can still be used in pointer expressions, as long as it is not modified. The following example is a valid command that assigns [2] a value of 500.

 *( mang + 2 ) = 500 ; 

The above command is valid and will successfully compile because the bearing has not been changed.

According to Tutorialspoint

Previous lesson: Cursor pointer in C / C ++

Next article: Array of pointers in C ++