C Tutorial

C Tutorial C Language Environment Setup Execution flow of C program C printf and Scanf C Data type C Token Variable in C Operators in C Comments in C Escape Sequence in C C – Storage Classes C Decision control statement Loop Statement in C Break, continue and goto statement in C Type Casting in C Function in C Recursion in C String in C C Array Pointer in C Dynamic memory allocation C –Structure Nested Structure in C Union in C File Handling in C C pre-processor Static Function In C Sizeof In C Selection Sort In C Scope Of Variables In C Runtime Vs Compile Time In C Random Access Lseek In C Queue Implementation In C Pseudo Code In C Prototype In C Pointer To Pointer In C Pointer Arithmetic In C Passing Array To Function In C Null Character In C Merge Sort In C Macros In C Library Functions In C Memory Leak In C Int In C Goto And Labels In C Fibonacci Series In C Fflush In C Derived Data Types In C Data Types In C Const Vs Volatile In C Character Set In C Character Class Tests In C Calloc In C C Pointers Arrays In C Include In C Clrscr In C C Vs Java String Literals In C Types Of Pointers In C Variables In C Volatile In C Why C Is A Middle Level Language Infix To Postfix Program In C Ceil function in C LCM of two numbers in C Quick sort in C Static in C function pointer as argument in C Top Array Keywords in C Add two numbers using the function in C Armstrong program in C using function Array, Declaring Arrays and Array Initialization Limitations of Inline Function in C Merge and Merge sort with example in C Do-While Loop in C For Loop in C While-Loop in C Difference between while and do-while loop in C Array Of Structures in C Data Structures And Algorithms in C Types Of Structures In C How to Avoid Structure Padding in C Use of Structure in C Do WHILE LOOP in C Programming Examples For Loop in C Programming Examples Entry Control Loop in C Exit control loop in C Infinite loop in C Nested loop in C pow() function in C String Handling functions in C Prime Number code in C Factorial Program in C using For Loop Factorial Program in C Using While Loop Fibonacci Series in C Using For Loop Fibonacci series in C using while loop Prime Number Program in C using for Loop While Loop in C programming examples Built-in functions in C Assert() Function C vs Java Strings Call Back Function in Embedded C Else If Ladder fgets() function Ftell() Function getc() function getch() function gets() function Heap Sort Nested if-else statement Pi() Function Positioning of file Write() function abs() function in C Attributes in C C program to find factorial of a number using Recursion Ferror() in c fopen() function in C Fibonacci series program in C using Recursion Formatted Input and output function in C Snake Game in C User Defined Functions in C Beep() function in C Cbrt() function in C Hook() function in C Isalnum() function in C C Program to find the Roots of a Quadratic Equation C Switch Statements Difference between rand() and srand() function in C Difference between while and for loop in C Doubly Linked list in C Example of Iteration in C How to use atoi() function in C How to use floor() function in C How to use sine() function in C How to use Typedef Struct in C Integer Promotions in C C Program Swap Numbers in cyclic order Using Call by Reference C Program to Find Largest Number Using Dynamic Memory Allocation C Program to Find the Largest Number using Ternary Operator C/C++ Program to Find the Size of int, float, double and char Find the Largest Three Distinct Elements in an Array using C/C++ Loop Questions in C Modulus on Negative Numbers in C Multiplication table program in C using For loop Nested Loops in C Programming Examples C Program for Mean and Median of an Unsorted Array Results of Comparison Operations in C and C++ Reverse a Stack using Recursion in C Simple hash() function in C strcat() Function in C Sum of N numbers in C using For loop Use of free() function in C Write a program that produces different results in C and C++ C Function Argument and Return Values Keywords in C Bank management system in C Calendar application in C Floor() Function in C Free() Function in C How to delete a file in C How to move a text in C Remove an element from an array in C Unformatted input() and output() function in C What are linker and loader in C fork() in C GCD program in C Branching Statements in C Comma Operator in C Control statement in C Double Specifier in C How to create a binary file in C Long int in C Palindrome Number in C Pure Virtual Function in C Run Time Polymorphism in C Types of Array in C Types of Function in C What is a buffer in C What is required in each C Program Associativity of Operators in C Bit Stuffing Program in C Actual and Formal Parameters Addition of two Numbers in C Advantages of function in C

Arrays in C

An array is a derived data type in C. It is the collection of homogeneous data types in contiguous memory locations. Imagine having to store the marks of 60 students in a class. To store that many values, initializing 60 different int variables is one choice but is risky, time taking and complicated to access each variable. That is when; we store all the values under a single name- An array.

 It can store primitive data types like int, char, etc., as well as derived data types like pointers, structures etc. Each element inside the array can be accessed by its index. So, by using an array, we can store and access the data easily.

Syntax:

Declaration:

data_type name[size];

Here, data_type refers to the data type of all the items we want to store in the array, name is the identifier we give to the array.

We can also initialize the array at the time of declaration. Like:

data_type name[size] = {value1, value2,…};

data_type name[] = {value1, value2,…}; is also valid. [declaring the size is not mandatory]

Example

int marks[60]

Inside an Array:

To access and initialize the data items in the array, we use index of an array which starts from 0 to size-1.

Ex: int arr[7]

arr[0]arr[1]arr[2]arr[3]arr[4]arr[5]arr[6]

Example:

#include<stdio.h>
void main()
{
	int marks[5], I;
	marks[0] = 20;
	marks[1] = 30;
	marks[2] = 40;
	marks[3] = 45;
	marks[4] = 50;
	printf(“%d”,arr[2]);
}

Output:

40

Mechanism:

First, we declared an array with size 5. Then, we initialized the values using index. Now, we printed the value stored in 2nd index of the array which is 40.

Printing all the values in an Array:

To print all the values of an array, we cannot just print the array, because, it consists of many values. So, for that we use a for loop to traverse to every single value of the element and then print it.

Example:

#include<stdio.h>
void main()
{
	int arr[5] = {20,34,56,23,12},i;
	for(i=0;i<5;i++)
	{
		printf(“%d\n”,arr[i]);
	}
}

Output:

20
34
56
23
12

Advantages of using an Array:

  • Contains multiple variables under a single name.
  • Easy to sort elements
  • Easy to perform matrix operations.
  • Used for CPU Scheduling.
  • We can access elements easily
  • Less time consuming and decreases the length of the code.

Disadvantages of using an Array:

  • Fixed size: The size we give at the time of declaration of the array is fixed and can’t be modified dynamically.

Types of Arrays:

ARRAYS IN C

1. One-dimensional array: It is also called as a vector. These are simple arrays with subscript-1. [A Subscript is either the notation for number of rows or number of columns or both].

Syntax:

data_type name[size];

Example:

int arr[5];

2. Multi-dimensional Array:

Simply, It can be defined is “ARRAY OF ARRAYS”. Data stored in tabular forms. Ex: Two-dimensional arrays-a[2][2]; three dimensional arraya-a[2][2][2]

Syntax:

Data_type array_name[size1][size2]….[sizeN]

Two-dimensional Array: It is the representation of elements in rows and columns [subscript-2]. It is organized like a matrix.

Syntax:

Data_type name[rows][columns];

Example:

int arr[2][2];

int arr[2][2] = {{1,2},{3,4}};

Inside the array:

arr[0][0]arr[0][1]
arr[1][0]arr[1][1]

arr[0][0]-> Element in 0th row index and 0th column index

arr[0][1]-> Element in 0th row index and 1st  column index

arr[1][1]-> Element in 1st row index and 1st  column index

arr[1][0]-> Element in 1st row index and 0th column index

            Example Program:

#include<stdio.h>
	void main()
	{
		int i=0,j=0;
		int arr[2][2] = {{1,2},{3,4}};
		for(i=0;i<2;i++)
		{
			for(j=0;j<2;j++)
			{
				printf(“%d “,arr[i][j]);
			}
			printf(“\n”);
		}
	}

            Output:

1 2
3 4

            Mechanism: In the program, we initiated a two dimensional array and gave values to it. Now, to access the members of the array, we need to take two loops to access both rows and columns. The first loop is to iterate through the columns and the second one is to iterate the rows. The second loop is nested inside the first loop.

//To input the elements into the array

#include<stdio.h>
void main()
{
	int m,n,arr[m][n],i,j;
	printf(“Enter the number of rows: “);
	scanf(“%d”,&m);
	printf(“Enter the number of columns: “);
	scanf(“%d”,&n);
		for(i=0;i<m;i++)
		{
			for(j=0;j<n;j++)
			{
				printf(“arr[%d][%d]: “,i,j);
				scanf(“%d”,&arr[i][j]);
			}
		}
		printf(“The array looks like: \n”);
		for(i=0;i<m;i++)
		{
				printf(“\n”);
				for(j=0;j<n;j++)
				{
					printf(“%d\t”,arr[i][j]);
				}
		}
	}

Output:

Enter the number of rows: 3

Enter the number of columns: 3

Enter arr[0][0]: 56  

Enter arr[0][1]: 10  

Enter arr[0][2]: 30 

Enter arr[1][0]: 34 

Enter arr[1][1]: 21

Enter arr[1][2]: 34   

Enter arr[2][0]: 45

Enter arr[2][1]: 56

Enter arr[2][2]: 78  

The array looks like:

56      10      30

34      21      34

45      56      78     



ADVERTISEMENT
ADVERTISEMENT