What is a two-dimensional array in C language?

An array is a group of related items that store with a common name.

Syntax

The syntax is as follows for declaring an array −

datatype array_name [size];

Types of arrays

Arrays are broadly classified into three types. They are as follows −

• One – dimensional arrays
• Two – dimensional arrays
• Multi – dimensional arrays

Initialization

An array can be initialized in two ways, which are as follows −

• Compile time initialization.
• Runtime initialization.

Two multidimensional arrays

These are used in situations where a table of values have to be stored (or) in matrices applications.

Syntax

The syntax is given below −

datatype array_ name [rowsize] [column size];

For example int a[5] [5];

Following is the C Program for compile time initialization −

Example

#include<stdio.h>
main ( ){
   int a[3][3] = {10,20,30,40,50,60,70,80,90};
   int i,j;
   printf ("elements of the array are");
   for ( i=0; i<3; i++){
      for (j=0;j<3; j++){
         printf("%d \t", a[i] [j]);
      }
      printf("\n");
   }
}

Output

The output is stated below −

elements of the array are:
10 20 30
40 50 60
70 80 90

Following is the C program for runtime initialization −

Example

#include<stdio.h>
main ( ){
   int a[3][3] ,i,j;
   printf ("enter elements of array");
   for ( i=0; i<3; i++){
      for (j=0;j<3; j++){
         scanf("%d", &a[i] [j]);
      }
   }
   printf("elements of the array are");
   for ( i=0; i<3; i++){
      for (j=0;j<3; j++){
         printf("%d\t", a[i] [j]);
      }
      printf("\n");
   }
}

Output

The output is stated below −

Enter elements of array :
1 2 3 4 5 6 7 8 9
Elements of the array are
1 2 3
4 5 6
7 8 9

Given below is the C program to calculate sum and product of all elements in an array using run time compilation −

Example

#include<stdio.h>
void main(){
   //Declaring the array - run time//
   int A[2][3],B[2][3],i,j,sum[i][j],product[i][j];
   //Reading elements into the array's A and B using for loop//
   printf("Enter elements into the array A: \n");
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         printf("A[%d][%d] :",i,j);
         scanf("%d",&A[i][j]);
      }
      printf("\n");
   }
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         printf("B[%d][%d] :",i,j);
         scanf("%d",&B[i][j]);
      }
      printf("\n");
   }
   //Calculating sum and printing output//
   printf("Sum array is : \n");
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         sum[i][j]=A[i][j]+B[i][j];
         printf("%d\t",sum[i][j]);
      }
      printf("\n");
   }
   //Calculating product and printing output//
   printf("Product array is : \n");
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         product[i][j]=A[i][j]*B[i][j];
         printf("%d\t",product[i][j]);
      }
      printf("\n");
   }
}

Output

The output is stated below −

Enter elements into the array A:
A[0][0] :2
A[0][1] :3
A[0][2] :1
A[1][0] :2
A[1][1] :4
A[1][2] :5
B[0][0] :1
B[0][1] :2
B[0][2] :3
B[1][0] :5
B[1][1] :6
B[1][2] :7
Sum array is :
3 5 4
7 10 12
Product array is :
2 6 3
10 24 35