Question

Let a 2 - D array declaration be char Arr[100][100] store data such that the base address of the array is 0. Additionally, considering the array to be byte addrassable, what would be the address of element stored at arr[20][30].

Answer 1

We know : 2D arrays are stored by default in Row-major order in C-programming language.
A[i][j] = base address + [(i - start index) $\times$ n + (j - start index)] $\times$ s.
Where,
m = no. of rows,
n = no of columns,
S = memory size,
Given, base address = 0,
start index = 0, s = 1,
arr [100][100] = a[m][n] $\approx$ arr[0 .... 99][0 ..... 99]
$\therefore$ m = 100, n = 100
Arr[20][30] = 0 + [(20 - 0) $\times$ 100 + (30 - 0)] $\times$ 1
= 2000 + 30
Arr[20][30] = 2030.