Pointer Arithmetic

Adding n to a pointer moves it by n elements, not n bytes.

Intermediate

int data[4] = {10, 20, 30, 40};
int *p = data;
*(p + 2);      // 30  — same as data[2]
p++;           // now points to data[1]

If int is 4 bytes, p + 1 advances the address by 4. Subtracting two pointers into the same array gives the number of elements between them. Arithmetic outside the array (except one past the end) is undefined behaviour.

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