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LB : Lower Bound of subscript (if not specified, it will be “0”) : 0
I : Subscript of the element whose address is to be calculated.
Let us do some more examples given below.
1. Given the base address of an array B[1200…..1800] as 980 and size of each element is 4 bytes in the memory.
Find the address of B[1340].
Ans. The given values are: B = 1340, LB = 980, W = 4, I = 1340
Address of A [ I ] = B + W * ( I - LB )
= 980 + 4 * (1340 - 1200)
= 980 + 4 * 140
= 980 + 280
= 1260
2. An array ar[900 …. 2505] is stored at the base address 1500. Each element of the array occupies 8 bytes in the
memory. Find the address of :
a. ar[1100]
b. ar[2420]
Ans. a. The given values are: B = 1500, LB = 900, W = 8, I = 1100
Address of A [ I ] = B + W * ( I - LB )
= 1500 + 8 * (1100 - 900)
= 1500 + 8 * 200
= 1500 + 1600
= 3100
b. The given values are: B = 1500, LB = 900, W = 8, I = 2420
Address of A [ I ] = B + W * ( I - LB )
= 1500 + 8 * (2420 – 900)
= 1500 + 8 * 1520
= 1500 + 12160
= 13660
9.6.2 Address Calculation in Two-Dimensional Arrays
Column Index
0 1 2 3
0 10 22 94 87
Row
index 1 100 104 108 112
2 100 104 108 112
The address of an element in two-dimensional arrays can be calculated in two different forms:
a. Row Major System:
Address of A [ I ][ J ] = B + W * [ N * ( I – Lr ) + ( J – Lc ) ]
1 2 3 4 5 6 7 8 9 10 11 12
Arranged in Row major wise
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