array in cpp

C++ provides a data structure, the array, which stores a fixed-size sequential collection of elements for the same data type.

single-dimension

Declaring Arrays:
To declare an array in C++, the programmer have to specifies the type of the elements and the number of elements ( array size) :

type arrayName [ arraySize ];
example :
initialization array
int score[5];
initialization array with assignment
int score[5] = {80,70, 90, 99, 100};
int score[] = {80,70, 90, 99, 100};

score[4] = 95;
it will assign the value to the array at the index 4 to 95 so the new values of array are {80,95, 90, 99, 100}

programmer can also get a value from array in any index

int myscore = score[4];
// myscore = 100

Example :

#include <iostream>
using namespace std;
  
int main ()
{
   int arr[ 10 ]; // arr is an array of 10 integers 
   // initialize elements of array arr to 0          
   for ( int i = 0; i < 10; i++ )
   {
      arr[ i ] = i * 10 +i; // set element at location i to i * 10+i
   }
  
   // output each array element's value                      
   for ( int j = 0; j < 10; j++ )
   {
      cout << "array at index "<<j <<" = "<< arr[ j ] << endl;
   }
 
   return 0;
}

Multi-dimensional arrays

example array 2 dimensional :

#include <iostream>
using namespace std;

int main ()
{
   int arr[ 10 ][5]; // arr is an array of integers for 10 rows and 5 cols
   // initialize elements of array arr to 0
   for ( int i = 0; i < 10; i++ )
   {
       for(int j=0;j<5;j++){
            arr[ i ][j] = i * 10 +j; // set element at location i to i * 10+i
       }

   }

   // output each array element's value
   cout<<"j ->\t0\t1\t2\t3\t4"<<endl;
   cout<< "k|"<<endl;
   for ( int j = 0; j < 10; j++ )
   {
       cout <<j<<"\t";
       for(int k=0;k<5;k++){
            cout << arr[ j ][k] <<"\t";
       }
       cout<<endl;
   }
   return 0;
}