Arrays:
An array is a group of consecutive memory location with same name and type. An array is the 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 numbers of elements in the array is called
length of array. Arrays are used to store large amount of similar type of data.
Advantages of Arrays:
Some advantages of arrays are as follows:
- Arrays can store a large amount of values with single name.
- Arrays are used to process many values easily and quickly.
- The values stored in array can be sorted easily.
- A search process can be applied on array easily.
How to access array elements:
Each element in the array is accessed with reference to its position of location in the array. This position is called subscript or index . The index of the first element is 0 and the index of the last element of array is length-1. Each element of the array has unique index . The values of index is written in brackets / subscript operator ([] ) along with the name of the operator.
One-Dimensional Array:
A type of array in which all elements are arranged in the form of a list is known as one-dimensional array. It is also called single dimensional array or linear list. It consists of one column or one row. The process of specifying array name, length and data type is called array declaration.
Syntax:
The syntax of the declaring one-dimension array is as follows :
Data_Type Identifier[Length];
Data_Type: It indicates the data types of the values to be stored in the array.
Identifier: It indicates the name of the array.
Length: It indicates total number of elements in the array. It must be a literal constant or symbolic constant.
For example:
int marks[5];
In this example an integer array marks is declared of five elements. It allocates the five consecutive locations in memory. The index of first element is 0 and index of last element is 4.
Array Initialization:
The process of assigning values to array elements at the time of declaration is called
array initialization. The values are separated with
comma(
,) and enclosed in
braces (
{}). If the number of initialized values are less then the size of array, the remaining array elements are initialized to zero.
Syntax:
data_type identifier[Length] = {List of values};
Example:
int marks[5] ={85,98,95,80,91};
The above statement declares an array of marks with 5 elements. It also initialized the array with values like at
marks[0] is initialized to 85
marks[1] is initialized to 98
marks[2] is initialized to 95
marks[3] is initialized to 80
marks[4] is initialized to 91
Write a C++ program that input five integers from the user and store them in an array , display them without using loops.
#include <iostream.h>
#include <conio.h>
int main ()
{
int num[5];
cout<<"Enter five number: " ;
cin>> num[0] ;
cin>> num[1] ;
cin>> num[2] ;
cin>> num[3] ;
cin>> num[4] ;
cout<<"The values in array are: \n " ;
cout<<num[0]<<endl ;
cout<<num[1]<<endl ;
cout<<num[2]<<endl ;
cout<<num[3]<<endl ;
cout<<num[4]<<endl ;
return 0;
}
Write a C++ program that input five integers from the user and store them in an array , display them using loops.
#include <iostream.h>
#include <conio.h>
int main ()
{
int num[5] , i ;
for (i= 0; i < 5; i++)
{
cout<<"Enter number: " ;
cin>> num[i] ;
}
cout<<"The values in array are: \n " ;
for (i= 0; i < 5; i++)
{
cout<<num[i]<<endl ;
}
return 0;
}
Two-Dimensional Array:
Two-dimensional array is considered as a table that consist of
rows and
columns. It is referred with the help of two indexes. One index is used for row and the second index is for column of the element.
Syntax:
Data_type Identifier[row][column];
Example:
int marks[5][1]
The above statements declares a two-dimensional array with five rows and 1 column.
Write a C++ program that input integers values from the user and store them in an array of 3 rows and 2 columns.
#include <iostream.h>
#include <conio.h>
int main ()
{
int num[3][2] , i , j ;
for (i= 0; i < 3; i++)
for (i= 0; i < 2; i++)
{
cout<<"Enter number: " ;
cin>> num[i][j]
;
}
for (i= 0; i < 3; i++)
{
for (i= 0; i < 2; i++)
cout<<num[i][j];
cout<<endl ;
}
Programs:
