An array is a collection of similar data types (like int, float, or char), which takes memory in a contiguous fashion in Primary memory locations.
We can declare an array in C as
int arr[50];
Where arr is an array with can hold 50 elements of integer types.
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Two Type of array:
1). Single/One Dimensional array
2). Multi-Dimensional Array
One Dimensional Array
Declaration of one dimensional array:
An array can be declared with the bracket punctuators [ ], as shown in the below syntax:
Data_Type Array_Name[Number_Of_Elements]
The below example shows a declaration of an array having the capacity to hold 50 elements of type integers and the name of that array is arr :
int arr[50];
Initializing the array:
We can initialize an array in C by assigning value to each index one by one or by using a single statement as follows −
Example 1 :
Assign one value each time to the array
int arr[50];
arr[0]=12;
arr[1]= 43;
arr[2] = 14;
.
.
.
.
.
arr[49] = 54;
Example 2:
Using a single statement
int arr[5] = {10,32,11,45,38};
Program in C to implement One dimensional array:
#include <stdio.h>
int main () {
int n[50]; /* n is an array of 50 integers */
int i,j;
/* initialize elements of array n to 0 */
for ( i = 0; i < 50; i++ ) {
n[ i ] = i + 50; /* set element at location i to i + 50 */
}
/* output each array element's value */
for (j = 0; j < 50; j++ ) {
printf("Element[%d] = %d\n", j, n[j] );
}
return 0;
}
Multidimensional Arrays
We can say a Multidimensional array is an array of arrays. Two Dimensional arrays is also a multidimensional array. In a Multi-Dimensional array, elements of an array are arranged in the form of rows and columns.
Multidimensional array stores elements in tabular form which is also known as in row-major order or column-major order.
Declaration of Multi-dimensional Array
data_type array_name[size1][size2]….[sizeN];
data_type: It defines the type of data that can be held by an array. Here data_type can be int, char, float. etc.
array_name: Name of the array
size1, size2,… ,sizeN: Sizes of the dimensions
Pictorial representation of a multidimensional array
number_of_arrays: number of arrays which flow in the z-axis
rows: number of the rows in the y-axis
columns: number of the columns flow in the x-axis
Two-dimensional array
int arr1[10][20];
Three dimensional array
int arr2[10][20][30];
Initialization of the Multidimensional array
Two-dimensional array
int arr[5][4]={
{1,2,3},
{2,3,4},
{3,4,5},
{4,5,6},
{5,6,7}
};
Program in C to implement Two dimensional Array
#include<stdio.h>
int main(){
int i=0,j=0;
int arr[5][4]={{1,2,3},{2,3,4},{3,4,5},{4,5,6},{5,6,7}};
//traversing 2D array
for(i=0;i<5;i++){
for(j=0;j<4;j++){
printf("arr[%d] [%d] = %d \n",i,j,arr[i][j]);
}//end of j
}//end of i
return 0;
}
Three Dimensional Array
int test[2][3][4] = {
{ {5, 6, 1, 9}, {10, -3, 91, 61}, {73, 32, 83, 22} },
{ {13, 43, 56, 36}, {25, 9, 93, 55}, {39, 21, 74, 6} }
};
Program in C to implement Three-dimensional array
#include <stdio.h>
int main()
{
int i, j, k, test[2][3][4];
printf("Enter 24 values for 3-D array: \n");
for(i = 0; i < 2; ++i) {
for (j = 0; j < 3; ++j) {
for(k = 0; k < 4; ++k ) {
scanf("%d", &test[i][j][k]);
}
}
}
printf("\nDisplaying the values of 3-D array:\n");
for(i = 0; i < 2; ++i) {
for (j = 0; j < 3; ++j) {
for(k = 0; k < 4; ++k ) {
printf("test[%d][%d][%d] = %d\n", i, j, k, test[i][j][k]);
}
}
}
return 0;
}