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c++arrayspointersmemory-address

Why is the address of an array the same the array converted to a pointer?

int t[10];

int * u = t;

cout << t << " " << &t << endl;

cout << u << " " << &u << endl;

Output:

0045FB88 0045FB88
0045FB88 0045FB7C

The output for u makes sense.

I understand that t and &t[0] should have the same value, but how come &t is also the same? What does &t actually mean?

Solution

  • When t is used on its own in the expression, an array-to-pointer conversion takes place, this produces a pointer to the first element of the array.

    When t is used as the argument of the & operator, no such conversion takes place. The & then explicitly takes the address of t (the array). &t is a pointer to the array as a whole.

    The first element of the array is at the same position in memory as the start of the whole array, and so these two pointers have the same value.