1. By Hector M Lugo-Cordero September 17, 2008
Arrays and Pointers
By Hector M Lugo-Cordero
September 17, 2008
Department of Electrical and Computer Engineering

2. The Department of Electrical and Computer Engineering
Outline
Static arrays
Pointers
Dynamic Arrays
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3. The Department of Electrical and Computer Engineering
Static Arrays
int data[] = {1, 2, -4, -2, 5};
string test[4];
test[0] = “Bob”;
test[1] = “Apu”;
test[2] = “Ada”;
test[3] = “Isa”;
char abc[] = {‘a’, ‘b’, ‘c’};
Indexes go from 0 to N – 1; where N is the length (number of elements) of the array.
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Static Arrays (cont.)
for(int i = 0; i < sizeof(data)/sizeof(int); ++i){
cout << data[i] << endl; }
sizeof(x): returns the number of bytes that x occupies in memory.
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Pointers
Variables that store the reference (memory address) of a value.
Memory management functions are in cstdlib.
malloc
calloc
realloc
free
NULL
Unary Operators *
&
Can be the memory address or to modify a parameter a function
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Pointers (cont.)
Other ways of using pointers
int* pData = &data;
cout << pData << endl; //displays where data is stored
cout << *pData << endl; //displays what is inside of data
pData = &data
*pData = data
++pData: moves the pointer to the next memory position.
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Dynamic Arrays
Dynamic arrays change size at running time in contrast to static ones that stay with fix size.
Arrays and pointers are the same.
int* pData = (int*)calloc(3, sizeof(int));
int pData[3];
int* pData = new int[3];
Dynamic allocation
pData = (int*)realloc(pData, sizeof(pData)/sizeof(int)); //WHAT HAPPENS IF YOU DON’T DO THIS????
Another way of writing strings
char* mystring = (char*)malloc(10)
A char is of size 1 byte
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Questions? ?
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