### Array

Array is a collection of elements of the same type.

Array size is the number of elements it can contain, array size cannot be altered after declaration.

Each element inside the array has an unique index number which is used to access them.

Index number starts from 0

Array declaration

``` variable type variable_name [ array size ]; /*example array of double type with array size 10*/ double example[10]; ```

Array declaration with element initialization

``` variable type variable_name [ array size ] = { element1, element2 ,... }; /*example array of int type with array size 5*/ int prime[5] = {2,3,5,7,11} ; ```

An illustrated sample of above array is shown below:

prime
 Index Value 0 1 2 3 4 2 3 5 7 11

prime[ 0 ] = 2

### Practice

using namespace std ;

int fibonacci [10] = {1,1,2,3,5,8,13,21,34,55}

for( int counter = 0; counter <= 9; counter++)

{

cout<<"fibonacci["<< counter << "] = " << fibonacci[counter] << endl;

}

### Output

//When counter =
fibonacci[ 0 ] = 1

//Whole output
fibonacci[ 0 ] = 1
fibonacci[ 1 ] = 1
fibonacci[ 2 ] = 2
fibonacci[ 3 ] = 3
fibonacci[ 4 ] = 5
fibonacci[ 5 ] = 8
fibonacci[ 6 ] = 13
fibonacci[ 7 ] = 21
fibonacci[ 8 ] = 34
fibonacci[ 9 ] = 55