A variable containing the address of another variable is called a pointer.
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add ax, [pointer] |
add ax, SWORD PTR [pointer] |
.data
array SWORD 10, 20, 30, 40
pointer DWORD array
.code
mov ecx, LENGTHOF array
mov eax, 0
L1: add ax, [pointer]
add pointer, 2
loop L1
call WriteInt
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.data
array SWORD 10, 20, 30, 40
pointer DWORD array
.code
mov ecx, LENGTHOF array
mov eax, 0
L1: add ax, SWORD PTR [pointer]
add pointer, 2
loop L1
call WriteInt
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| Output | Output |
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[pointer]gives the contents of the variablepointer. -
After “
mov esi, pointer”,[esi]dereferences the offset from the variablepointerand obtains the contents of memory.
add ax, [esi] |
add al, [esi] |
.data
array SWORD 10, 20, 30, 40
pointer DWORD array
.code
mov ecx, LENGTHOF array
mov eax, 0
mov esi, pointer
L1: add ax, [esi]
add esi, 2
loop L1
call WriteInt
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.data
array SWORD 0102h, 0304h, 0506h
pointer DWORD OFFSET array
.code
mov ecx, 6
mov eax, 0
mov esi, pointer
L1: add al, [esi]
inc esi
loop L1
call WriteHex
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| Output | Output |
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“I’m not arguing, I’m just explaining why I’m right.” ― Unknown |