ARRAY IN C++ -VARSHAA.M MAHESHA.V

• An array is a group of consective memory locations with same name and data type.

• Simple variable is a single memory location with unique name and a type. But an Array is collection of different adjacent memory locations. All these memory locations have one collective name and type.

• The memory locations in the array are known as elements of array. The total number of elements in the array is called length.

• The elements of array is accessed with reference to its position in array, that is call index or subscript.

WHAT IS ARRAY?

DECLARATION OF AN ARRAY:Like a regular variable, an array must be declared

before it is used. A typical declaration for an array in Visual C++ is:

type name [elements];

type is a valid type (like int, float...) name is a valid identifier elements field (which is always enclosed in

square brackets []), specifies how many of these elements the array has to contain.

EXPLANATION:

INT NUM[6]

size of the array Base name of type array

ADVANTAGES OF ARRAY:Arrays can store a large number of value with single name.

Arrays are used to process many value easily and quickly.

The values stored in an array can be sorted easily.

The search process can be applied on arrays easily.

EG. PROGRAM:

TYPES OF ARRAY:

Single dimensional arrayTwo dimensional arrayMulti dimensional array

ONE DIMENSIONAL ARRAY:A one dimensional array is one in which one subscript /indices specification is needed to specify a particular element of array

Declaration :Data_type array_name [size of array ];

Eg:Int num[10];

EXAMPLE PROGRAM:

MEMORY REPRESENTATION:num[0] num[1] num[2] num[3] num[4] num[5] num[6] num[7] num[8] num[9]

2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 starting Address of location

Total memory in bytes that an array is occupied :

Size of array=size of array*size of(base type) Hear, 10*2=20 

39 56 23 98 6 56 9 2 54 67

TWO DIMENSIONAL ARRAY:A 2-d array is an array in which each element is itself an array i.e int num[4][3] 0 1 2

0 1 2 3

No of rows

No of columns

No of element in 2-D array =M*N

Num [2][1]

EXAMPLE PROGRAM:

MEMORY REPRESENTATION:Total bytes= no of rows*no of columns*size of(base type) Memory reprsentation in 2-D array: char A [2][3] A[0][0] A[0][1] A[0][2] A[1][0] A[1][1] A[1][2]

5001 5002 5003 5004 5005 5006

MULTI DIMENSIONAL ARRAY: An array with dimensions more than two .The maximum limit of array is compiler dependent

Declaration:Data_type name [a][b][c][d][e][f]…….[n];

Array of 3 or more dimensional are not often use because of huge memory requirement and complexity involved

EXAMPLE PROGRAMS:

ARRAY INITIALIZATION:C++ provides the facility of array initialization at the time of declaration .General form of array initialization is as:Type array_name[size 1]…..[size N] ={vale list};

Eg:Int days_month[12]={31,25,29,03,31,19,20,31,18,20,31,29};

Char string[6]={‘a’,’r’,’g’,’y’,’d’,’\0’};

2-D array are also initialized in same way as linear array Int cube[4][2]={ 1,3,

4,6, 9,37, 5,78 };

UNSIZED ARRAY INITIALIZATION:

C++ allowed you to skip the size of array in an array initialization statement C++ automatically create an array big enough to hold all the initializers presentChar S1[] =“ first string ”;

you skip the size, you must give list of initializers so that C++ can calculate the size of array Int val []={3,5,6,2,8,9,6,4};Int cube [] [2] ={ 1,3, 67,7, 6,87, };

STRING AS ARRAY:C++ does not have a String data type ,it impairments string as 1-D character Arrray .A string as a character array is terminate by a null character ‘\0’

Char str 1 [11];

Char square [][]={ ‘first string’, ‘second string’, ‘third string’ };

SORTING ARRAYS:Sorting is a process of arranging the value of array in a particular order. An array can be sorted in two order.

oAscending Order oDescending Order

THANK YOU