Showing posts with label Accessing Array Elements. Show all posts
Showing posts with label Accessing Array Elements. Show all posts

Tuesday, March 8, 2016

Initialization of Single Dimensional Array

Single Dimensional Arrays in C can be initialized in the following way:
Method 1:
int rollnum[6]={5,3,32,9,2,10};
By this way, you specify the size of the array and initialize the values.
Method 2:
int rollnum[]={5,3,32,9,2,10};
You can even assign values to the array, without initializing the size of the array.
Method 3:
int rollnum[5];
int i;
for( i=0;i<5;i++ )
{
   rollnum[i] = i;
}
You can initialize the arrays this way too.

Accessing Array Elements

In C programming, you can access and operate arrays like variables in C. To access i'th element in the array you need to write as <array name>[i-1]. Since the array index starts from 0.
For example:
scanf("%d",&rollNum[3]);
/* statement to insert value in the forth element of array rollNum[]. */

scanf("%d",&rollNum[i]);
/* Statement to insert value in (i+1)th element of array rollNum[]. */
/* Because, the first element of array is rollNum[0], second is rollNum[1], ith is rollNum[i-1] and (i+1)th is rollNum[i]. */

printf("%d",rollNum[0]);
/* statement to print first element of an array. */

printf("%d",rollNum[i]);
/* statement to print (i+1)th element of an array. */
One thing you should remember is that, when you have declared roll_Number[6] array of size 6, your valid access to the array is only from 0 to 5. If you try to access any invalid index like 8, 10 etc. compiler do not throw any error, it will be throw a runtime error. Usually a program crash due to invalid memory manipulation i.e. it would cause a segmentation fault.