Array Index starts with zero
In most common programming languages, the indexing in array starts with zero (0). The reasons behind this are:
In programming languages like C and C++, the array name refers to the
location in the memory which means
the array name simply points to first element
of the array and array[n] refers to the location of n-elements away from the
first element. Here, n is used
as an offset from the array’s first element. So the first element is at zero
(0) distance away from the array. That’s why array index starts with zero.
Performance overhead:
Zero (0)-based
index allows array[n]
to be implemented as *(array + n).
If index were one (1)-based, compiler would need to generate *(array + n - 1),
and this "-1" has some
performance overhead. As this extra subtraction instruction lowers the
performance to low extent but this adds up to a lot when one has to write
for the Compiler.
And the common programming languages developed after C and C++ follows the same design logic for the indexing of the array.
Here is the proof:
#include <stdio.h>
int main()
{
int array[5] =
{1, 2, 3, 4, 5};
printf( "Array
location: %p\n", array );
printf( "Array location of first element: %p\n", array[0] );
}
Output:
Array location: 0x7ffde4bf25b0
Array location of first element: 0x7ffde4bf25b0
See the output above, both array and array[0] refers to the same memory location.
